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LEGAL METROLOGY

Rocío M. Marbán

Julio A. Pellecer C.

2003

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To contact the authors:

2001 Producción y Servicios Incorporados S.A.Calzada Mateo Flores 5-55, Zona 3 de MixcoGuatemala, Centro AméricaTel.: (502)431-0662Fax: (502)434-0692email: psi2001@itelgua.com

ISBN: 99922-770-3-3© OEA, 2003

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This document is published under the joint sponsorship of SIMand PTB.

The Inter American Metrology System, SIM (SistemaInteramericano de Metrología, Normalización, Acreditación yCalidad) is the regional organisation for metrology in America,comprising national metrology institutes from the 34 membernations represented at the Organisation of the American States,OAS, which acts as its Executive Secretariat.

The Physikalisch-Technische Bundesanstalt, PTB , is thefederal highest authority for metrology in the Federal Republic ofGermany.

The opinions stated in this document are not necessarily opinionsof the OAS or the PTB, their bodies or staff.

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CONTENTS

Acknowledgements vii

Presentation ix

Synopsis xi

1. General aspects 1

1.1. Is legal metrology necessary? 41.2. For whom is it necessary? 71.3. Why is it necessary? 101.4. What is its scope? 141.5. Study of the situation of legal metrology in

a country 171.5.1. Study of the legal framework of

metrology 181.5.2. Identification of elements subject to

quantity measurements 19

2. Basic concepts 21

2.1. Metrology 222.2. Legal metrology 222.3. Type approval 242.4. Verification 252.5. Certification 262.6. Accreditation 262.7. SI Units 272.8. Calibration 28

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2.9. Traceability 282.10. Intercomparisons 292.11. Penalties 302.12. Metrological evaluation 312.13. Maintenance 312.14. Conformity assessment 322.15. Control of pre-packaged goods 322.16. Metrological control 332.17. Market surveillance 34

3. Scope and impact of legal metrology 35

3.1. Official rulings 393.1.1. Maintenance of measurement standards and transfer of units 423.1.2. Type or model approval 433.1.3. Controls (verifications, certifications, conformity assessment, etc.) 453.1.4. Supervision of organisations in charge of particular control activities 473.1.5. Accreditations 483.1.6. Market surveillance 493.1.7. Control of pre-packaged products 51

3.2. Commerce 533.3. Health 543.4. Safety 553.5. Environment 563.6. Development of enterprises 58

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4. Legal metrology in the juridical system of a country 61

4.1. The law on metrology, other related laws and resolutions 64

4.2. The OIML model for a Law of Metrology 66

5. Administrative aspects 77

5.1. Public authorities involved in legal metrology – some models 78

5.2. Assignments 885.3. Administrative procedures 935.4. Fees, fines, financial aspects 94

6. Technical aspects 97

7. Regional and international legal metrology 101

7.1. The International Organisation of LegalMetrology, OIML 101

7.2. Europe 1057.2.1. Regional organisations in Europe 1057.2.2. The New Approach and the Global

Approach in Europe 1067.3. America 110

8. The future of legal metrology 113

9. Bibliography 117

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ACKNOWLEDGEMENTS

This book does not pretend to reinvent Legal Metrology, on thecontrary. Thus, although we state some personal convictions, whatwe strive to do is to make clear some of the concepts related to legalmetrology which are used over the world. We have studied manydocuments and carried out many personal interviews with the resultthat a large amount of what is here included is not original. It did notseem to us practical or necessary to state the specific reference ineach and every case; we refer the reader to the general bibliographyand plead the known adage that “to copy from a single author isplagiarism but to take from many is bibliographical research”.

We trust we will be forgiven this liberty and that the authors referredto will accept this recognition on our part of the merits of their pointof view.

There are individuals and organisations that have helped us in sucha way we feel bound to give them explicit recognition. Particularly,Oscar Harasic of the Office of Science and Technology of the OAS,Dieter Schwohnke, Wilfried Schulz, Eberhard Seiler, and Ms. StefanieReichertz of PTB in Germany, Dieter Ullrich from Mess- undEichwesen Niedersachsen, Michael Bosse-Arbogast from Metegra,Kai-Uwe Thase and his professional staff from Kellogs, Dieter Buerand Klaus Helmboldt from Eichamt Bremen, Jean-François Maganaof the BIML/OIML, Pierre Canavaggio of the Sous-Direction deMétrologie du Ministère d’Économie, Finances et Industrie in France,Ángel García San Román and Mrs. Carmen Sevilla Antón both fromthe Centro Español de Metrología, Mrs. Danièle Le Coz of the BIPM.

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We are well aware of possible deficiencies and omissions in thisdocument. To those who read it, we ask for their comments which,no doubt, will prove to be useful.

In any case, responsibility for the contents of this publication liessolely with the authors.

June 2003

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PRESENTATION

In every country, no matter its size or its level of development,Government has among its mandates to watch over the health andsafety of its population, the preservation of the environment, and fairtrade.

Current globalisation processes are making available to all, in anycountry, a wide range of goods and services, either produced locallyor imported.

All these require the establishment of laws and rules, standards andtechnical regulations, and the implementation of the mechanismsneeded for compliance. Usually, to ensure compliance demandscarrying out quantity measurements of diverse types, and theavailability of instruments, procedures or systems of measurementcapable of ensuring accuracy and reliability of the results.

This requires a national system that can support quantitymeasurements within the legal framework of the country – that is, alegal metrology system.

Organisations related to metrology in the Western Hemisphere havetaken up this issue and they think it is necessary to have a widerdiffusion of the main principles and of the current trends of legal

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metrology. This book has been written with that purpose in mind, it isaddressed to non-specialists and seeks to give them the essentialelements for knowledge of this field of endeavour.

Oscar HarasicRegional Coordinator of the Project Interamerican System forMetrology, Standardization, Accreditation and Quality,Organization of the American States, OAS.

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SYNOPSIS

It is a known fact that any activity in human organised life is doneunder the rules of law. Many human relations involve exchangesand imply quantity measurements; the application of the law in someaspects of exchange is the subject matter of Legal Metrology.

The bases of Metrology as the science of measurement were set upthousands of years ago and this required considerable scientific,technical, political, administrative, legal and economic efforts. In time,Metrology has become very important; the complexity of life indeveloped countries as well as relations between countries demandordinances to rule exchange relations, particularly those requiringquantity measurements.

These ordinances came about in answer to specific needs butnowadays, thanks to the good will of governments and the currentcommunication facilities, there is a legal structure concerningMetrology that is fairly developed and homogeneous.

One of its consequences is the existence of organisations such asthe international office of weights and measures, BIPM (BureauInternational des Poids et Mesures) and the InternationalOrganisation for Legal Metrology, OIML (Organisation Internationalede Métrologie Légale).

The legal structure of metrology in a country can be found by studyingits legal framework, as shown in the following diagram.

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Legal structure of metrology

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Sinopsis

Governments have advanced legal structures, some centralised, orbased on several organisations, others independent. Which of thesetrends will prevail is influenced by the characteristics of the economy.As an example, it is current practice in the European Union to reviselaws and procedures with the objective of realisation of the internalmarket while keeping national structures.

Legal Metrology should preferably be structured as a whole system;however, practice has been to solve problems as they appear.Nowadays, with market integration due to globalisation, once a needhas been identified it becomes urgent to satisfy it with laws,regulations and other resolutions, according to international practices.This while considering the actions that are being regulated, theorganisations in charge, the laws creating those organisations andtheir links and dependence, as well as the international treaties andconventions.

The actions of legal metrology require access to proper measurementstandards for base units, verifications that the measuring instrumentsand the measurement procedures in daily trade use are correct, andthe verification of measurement results when public interest isinvolved. These actions can be done directly by a legal metrologyorganisation or they can be delegated in part in a national system ofmetrology and accreditation (Chapter 1).

Actions will differ whether they are applied to measuring instrumentsthat are going to be manufactured, approved and sold on the market,or to instruments and measurement methods already in use(Chapter 2).

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The impact of legal metrology can be felt in fair trade and consumerprotection, personal health and safety, preservation of theenvironment, and in the performance of producers of goods andservices (Chapter 3).

Laws related to metrology are not identical, as they must fit withinthe national legal structure. In legal metrology, the authorities withspecific responsibility can act either as a group or individually, andthey have to cover rulings, responsibility for the metrologicalinfrastructure, technical activities, supervision, penalties. There areschemes for laws on metrology which have been prepared anddiscussed at the OIML and that can be adapted to different situationsin different countries (Chapter 4).

Administration of legal metrology varies between countries and sodo the responsibilities of each type of organisation involved. However,it is possible to outline some general ideas on administrativeprocedures and financial aspects including charges for services and,eventually, for penalties, in some countries of Europe and America(Chapter 5).

From a technical point of view, everything that will allow legalmetrology to do its work has to be studied. This includes, for instance,the setting up and operation of physical facilities, the proceduremanuals with details of the recommendations, protocols, andstandards to be used, scientific and technical expertise of personnelto guarantee the quality and credibility of all actions of legal metrology(Chapter 6).

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Sinopsis

The International Organisation for Legal Metrology, OIML, sets thegeneral principles and the international harmonisation of legalmetrology. Other similar organisations work towards harmonisationand co-ordination of legal metrology at a regional level; such are theInter American Metrology System, SIM, with its Legal MetrologyWorking Group, and the European Co-operation in Legal Metrology,WELMEC (Chapter 7).

In Europe there is a very strong trend towards what is called theNew Approach to product regulations and the Global Approachto conformity assessment. Based on these approaches, the Europeansingle market fixes only those essential requirements that willguarantee the certainty of measurement in instruments and the safetyof persons and the environment. Responsibility is placed step bystep with the manufacturer of the measuring instruments as long ashe can show that he has a quality system in place, recognised by acertification body (notified body) and supervised at regular intervalsby said body. This is a way of legislating in metrology that could beprofitably studied by other countries and regions (Chapter 7).

Technical progresses in measuring instruments and procedures arebringing about deep changes that will globalise legal metrology,resulting in a stronger international harmonisation and mutualagreements between countries and metrological organisations, withthe purpose of avoiding both unnecessary duplications and thecreation of non-tariff barriers to trade (Chapter 8).

Keeping in mind efforts such as the New Approach and the GlobalApproach, all those who are involved in legal metrology, whether

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they are government officials or not, can modify, create or adaptfundamental basic laws of legal metrology, identify their main needs,and satisfy them in harmony with the target markets.

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1. General aspects

Legal metrology is basic to guarantee correctness andequity in commercial transactions and to protect the healthand well-being of the members of society, as well as theenvironment.

Everyone benefits from the availability and implementationof a legal metrology system: individuals, both asconsumers and as entrepreneurs, and Government.

The actions of legal metrology require the guarantee ofaccess to proper measurement standards for the baseunits, verification that instruments and measuringprocedures of daily commerce are correct, and checkingof measurement results whenever the public interest isinvolved. These actions can be carried out directly by alegal metrology entity or be partially delegated in theframework of a national system of metrology andaccreditation.

This is an introductory book. Because much in it will be new:vocabulary, concepts, purpose, etc., we have limited its contentsto what was deemed essential and accessible. Our aim is to makeit useful to people from different fields who share an interest inlegal metrology such as lawyers, lawmakers, metrologists,government officials, entrepreneurs, consumers, etc.

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Broadly, we can say that legal metrology is that branch ofMetrology whose purpose is to verify the observance of technicaland legal standards related to measurement units, methods andprocedures of measurement, measuring instruments andmaterialised units. Its aim is to guarantee correctness and equityin commercial relations and to protect the health and wellbeing ofthe members of society, as well as the environment.

We are all of us familiar with weights and measures but we do notalways stop to reflect that their correct application is essential toprotect us as consumers and to maintain fair competition betweenenterprises. Legal metrology is one of the basic services that acountry’s government can offer to its population, whether we seethem as consumers or as elements of the productive andcommercial community.

Legal metrology infrastructure is a national asset; its influencemay be diffuse and not obvious but it represents a significantcontribution to a country’s development. As a public service, it isextremely useful to science, industry, commerce, health and theenvironment. If it is often not recognised as such, this is due inpart to the fact that as a service activity it is evaluated indirectlythrough its applications. Thus, it can be difficult to clearly justifyits existence and the support it demands.

In the present state of affairs, there are trends towardsglobalisation of world commerce, internationally distributedmanufacture, a growing complexity of products and services aswell as a growing concern for health and the safety and

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conservation of the environment. These subjects point to thegrowing importance of worldwide uniformity in measurements withthe concurrent presence of systems for accreditation and mutualrecognition of measurements.

Commercial agreements between countries and regions mayrequire signatories to accept the results of measurements carriedout by the other parties. This in turn influences the design andwork of the metrology organisations of a country and must beconsidered by authorities when evaluating needs and futureactions.

When there is no clear understanding in government and theproductive sector of the role of metrology and particularly of legalmetrology, the corresponding organisations find themselvescontinuously scrutinised and subject to revisions of their purpose,their goals and their programmes of work. In the long run, no oneis well served: neither government, nor industry or commerce,nor the population who, directly or indirectly, pays for the actionsand should benefit from them.

Practically all developed countries have an infrastructure thatincludes a metrology laboratory. More and more developingcountries are feeling the need of a metrological infrastructure,even if minimal, taking into account the precision level ofmeasurements required according to the properly identified needsof each country.

General aspects

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In legal metrology it will always be necessary to determine if theexpected benefits justify the expenditures made by thegovernment and by the users of measuring instruments. This isparticularly important for small countries facing the establishmentof an infrastructure and of a level of metrological services that uptill now have been non-existent or deficient. This requiresidentifying clearly what are the real needs, defining properpriorities, and addressing initially those actions with a strongerimpact on the population.

A national metrology organisation must also become well knownand of easy access to all, and it must become the main referencefor all questions having to do with measurements.

The first questions to ask are: is legal metrology necessary? forwhom? why?

We will try to give some answers to these questions.

1.1. Is legal metrology necessary?

By nature, Man tends to live in small or large groups, from familythrough tribe up to state. The group cohesion cannot be properlykept if everyone does as he wishes; to live together it is necessaryto accept a certain amount of discipline and whoever goes againstthe rules must know he is liable to suffer a certain penalty. Thishas given birth to a legal structure on which modern societies arebased.

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The search for the public interest in everything as pertains tomeasuring instruments and the use of national and internationalstandards, requires a legal basis. The laws and regulationsenforced by Government are the field of legal metrology and theGovernment acts directly when called upon to ensure correctnessof measurements for the public good. In general terms, wheneverthere can be conflict of interests or whenever incorrectmeasurement results can be detrimental to individuals or tosociety, everyone can trust the correctness of the measurementresults thanks to a governmental guarantee.

Legal metrology is the link between user and supplier that guardsthe interests of both. A judge may be called upon by either partyor by a third party. Thanks to legal metrology, he will be able toestablish the real amount of merchandise or product, to determinethe conditions of the measuring instruments used, or to take thenecessary provisions to avoid unfair practices or to impose legalpenalties on infractors.

Properly applied, legal metrology promotes economic and socialbenefits. For instance:

- it avoids unjustified payments by consumers for the thousandsof tons of products which are not received annually whenweighing instruments do not comply with legal requirementsor pre-packaged products do not have the correct amount,when fuel pumps are outside permissible tolerances, energymeters do not give correct readings, taximeters do not function

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correctly, clocks in parking meters do not register time properly,etc.

- it helps to avoid unfair practices and competition byencouraging ethics in all transactions and strengthening theprinciples of competitiveness,

- it avoids social tensions by helping any person to obtaineffective protection of its interests and rights in relationsbetween persons and between them and the Government,

- it strengthens the function of Government in the procurementof justice,

- it encourages entrepreneurs to comply with resolutions onmanufactures and services, etc.

Most governments have understood that one of theirresponsibilities is to develop and maintain the basic elements ofa national system for measurements and to see that it is properlyused.

There is no single model for a national system of metrology andpolicy should address the objectives for the country rather thanadopt traditional forms without the necessary study. Each countrymust decide its priorities, whether consumer protection or fair tradeor environmental protection. In any case, the system should bestimulant, not repressive, with reasonable taxes and rational useof available resources.

Metrology is becoming more and more complex so that the onlyoption when faced with growing expenses is to do a serious anddrastic evaluation of traditional priorities.

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To avoid solutions that may turn out to be too ambitious, particularlyfor measurement standards and equipment, the situation of thecountry should be studied in depth.

1.2.For whom is legal metrology necessary?

There is a mistaken trend to believe a priori that the only purposeof legal metrology is to protect defenceless citizens fromunscrupulous traders. This is not the case. Legal metrology seeksto make sure that in each and every case involving measurementsand their results, they will be reliable no matter who turns out tobe favoured. Modern metrology is based on universal scientificprinciples and as such is free from partialities. Legal metrologyhas to establish and coordinate the legal system that will guaranteethere is no distortion of this impartiality.

On the other hand, it is true that buyers do not always have themeans or the knowledge to protect their own interests. When atrader buys from another a certain product, most of the time bothhave their own means of verifying the amounts involved in thetransaction. The final consumer may not have this opportunity;he must thus rely on inspections carried out by the Governmentto ensure that transactions are correct – legal metrology protectsthose who cannot protect themselves.

Buyers with the lowest buying capacity are precisely those who,out of necessity, buy in small quantities and in relative terms thisis very important when incorrect measurements are detrimental

General aspects

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to them. Some countries have begun programmes to verify thatthe prices stored in the computers of bar code reading systemsare the same as the prices that appear on the products themselvesor on the labels or stickers on the stacks.

At home, people consume electricity, drinking water, gas, heat,all of them measured by meters whose reliability is tested andapproved by organisations within the legal metrology system. Thisis to ensure that these measuring devices will give correct resultsand that the specified error limits will be maintained during a periodof predefined duration (38).

Legal metrology also strives to protect all elements of society inaspects that are not strictly commercial when, as an example, itverifies measuring instruments used in medical diagnoses andtreatments, instruments used in measurements having to do withthe quality of water, of air and generally of the environment.

But, legal metrology is a universal protection; the trader loses ifhe gives larger amounts than those agreed upon and paid for,and the manufacturer loses if he is unable to measure properlyhis raw materials, his processes and his end products.

Because the true function of legal metrology lies in protecting theinterests of all those who take part in a transaction, a measuringinstrument which is detrimental to the trader must be rejected asstrongly as when the rights of the consumer are those involved.

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Legal metrology also promotes and protects industry andcommercial development by reducing unfair trade or prohibitingthe selling of products that do not comply with standards andregulations in force.

This means that it not only prevents undesirable behaviours, italso regulates commercial use and cares for strategic areas thatencourage production and competitiveness.

A first step should be to make an inventory of the legal metrologyneeds of a country, taking into account the scope of theorganisations charged with enforcement, the requirementsestablished by existing and future laws and regulations, and theavailable resources.

Two thirds of the member countries of the InternationalOrganisation of Legal Metrology, are developing countries. Thisorganisation advises (79), as the starting point of the infrastructurefor a legal metrology system, to carry out a careful inventory oflocal needs taking into account the number and types ofinstruments to be calibrated or verified, including their measuringrange, precision and where they are.

It is also important to develop a certain metrological point of viewin everyone and this is better done at the basic schooling level.Programmes of study for primary and secondary education shouldinclude aspects on quantities and their measurements.

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1.3. Why is legal metrology necessary?

There are many examples showing that for thousands of yearsback the leaders of human groups have felt the need ofestablishing certain measurement standards and regulations forthe use of resources of common interest. There is, for example,documentary evidence (99) that, under Tiglatpileser, Assyrians setup rules that can be seen as a nascent system of legal metrology:

- “measurements are made based on the amount of barleygrains necessary to sow a given area”;

- “irrigation channels are carefully drawn and kept, under thesurveillance of public authorities”;

- “landmarks are protected by severe penalties against whoevermoves them”.

Today, we have the advantage of not having to worry aboutdifferences, fluctuations or exchange rates of values for physicalmeasurements as we still have to do with currencies. We have astable system, internationally agreed upon, the InternationalSystem of Units, SI.

However, legal metrology varies between countries in aspectssuch as:

- the scope or extent of application,- the nature of the organisations responsible for implementation,- the nature and contents of the requirements and their

application,

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General aspects

- technical and economic development of the country as wellas the importance and resources that are assigned to legalmetrology.

Nowadays commercial transactions, industrial cooperation,telecommunications, are more and more internationalised. Theresult is that it becomes mandatory for all parties to use the samereferences, assign the same meaning to measurements, interpretthe charges similarly, agree on tolerances for raw materials andend products.

The same rigour must be applied to criteria on aspects of:

- safety (for instance in road traffic and in preventive measuresfor disasters such as fires)

- medical analysis and dosages (measurement errors indiagnoses and in therapy can cause death and, for good orbad, we rely more every day on measurements related tohealth), and

- environmental protection (for instance, to keep pesticides andheavy metals residues inside set limits).

Unfortunately there will always be persons, even if only a few,who will resort to fraudulent practices and harm given sectors ofsociety. Also, either through ignorance or negligence, there arenon-intentional frauds due to incorrect use of measuringinstruments and their negative impact is also significant. We mustkeep in mind that an erroneous measurement is damaging to theinjured party, whatever its cause.

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Legal metrology seeks to create trust and transparency betweeninvolved parties, based on tests and assays carried out byimpartial, competent and authorised organisations.

Metrology authorities guarantee accuracy by type approval andby verification of measuring instruments. Within the limits of anassured probability, the owners of the measuring instrument andtheir clients can trust this accuracy and refer – in case of doubt –to a test of the instrument done by the State.

The importance to a community of a correct supervision ofmeasures and measuring instruments cannot be underrated. Ifcommercial transactions and the economy itself are not to becomeunruly, the Government has to regulate the use of measuringinstruments and to exert a reasonable control of their users.

This is very important in developing countries where the economyis based on a limited number of agricultural or mineral products,petroleum, etc. and who have to import most of the manufacturedproducts and basic services they need. Sellers of such productsand services know quite well how to protect themselves frommeasurement uncertainties and this can mean that they may takeadvantage of the buyers.

On the other hand, it can be the seller who is the loser. In Bolivia,as an example, there were cases where producers or sellers ofraw sugarcane argued that the weighing instruments at the sugarmills did not give the correct amount.

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When products are subject to taxes, legal metrology helps to reacha fair appraisal of their value and a fair payment of taxes, with theconsequent benefits both to the national income as to the taxpayer.

At a personal level, legal metrology looks after the protection ofconsumers, contributing to a higher well-being and a better useof their buying power.

Manufacturing industry requires an increasingly higher precision.Many new technologies in common use are based on practicalapplications of recent discovery in physics. We can mention theuse of lasers and optical fibre, positioning and navigation systemsthat use signals from satellite atomic clocks which demanddimensional tolerances of 0,1 mm or less and time tolerances ofa few nanoseconds.

In 1993 (90), tolerances for the production of pistons in someautomobile motors were already on the order of about 7 mm,similar to that required in the manufacture of mechanical watches;what does this imply for repair shops?

Producers can voluntarily make use of the legal metrology systemto verify their instruments and their measuring procedures. Thisis of particular importance when deviations from specificationsare corrected in real time. Systems where the product is examinedafter its manufacture and there is a given percentage of rejectionscannot compete with those systems where all the products arewithin specifications (90).

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1.4. What is the scope of legal metrology?

Anyone who faces a measuring problem should be able to knowwhat is going to be measured, how to measure it and how toevaluate and report the results.

There are three different points of view: public authorities,professional sectors, and public opinion. When creating a legalmetrology system and its organisations, responsibilities andauthorities must be clearly defined.

To study future needs in legal metrology, one must know whatservices areas might be required. A list, althought incomplete,can include:

- industries, manufacturing and others,- commerce,- health and safety,- environmental protection,- science,- communications and transportation,- enforcement of government regulations,- energy generation and distribution,- surveying and navigation,- military services.

Main subjects of interest for the ruling legal metrology organisationare centred on:

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General aspects

- the protection of persons from incorrect measurementssignificant for health or safety, or to the economy of the country,through either direct actions or supervision,

- equal conditions for competitiveness derived from correctmeasurements,

- national, regional and international metrological harmonization- improvement of metrological capabilities in small and medium

sized industries,- traceability of measurements units in use to national and

international measurement standards,- dissemination of knowledge on measurement units to industry,

commerce and the people at large,- availability of competent specialized personnel for everything

relating to legal metrology,- regulation of expenses involved in measurements and their

supervision in accordance with set requirements,- use and promotion of uniform and equivalent procedures for

tests and supervision of measurements,- regional and international cooperation.

All aspects of measurement standards maintenance, traceabilitysystems, personnel training, and legal metrology, should bedeveloped within a system that will ensure the necessarycoherence between the different metrological activities of thecountry.

This requires a metrological infrastructure that includesinformation, education, expertise, physical resources, facilities for

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verification and calibration. At different levels, most countriesalready have a certain metrological infrastructure in place.

Basic elements of such an infrastructure can include:

- adoption of a system of units to be used throughout the country,- implementation of a national metrology laboratory or institute

to develop, maintain and disseminate standards and to transfernew measurement techniques to users,

- implementation of a legal metrology organisation to adviseGovernment of legal and regulatory matters and to take chargeof metrological supervision; this organisation may eventuallybe at the national metrology laboratory,

- a system for accreditation of tests and measurementslaboratories that satisfy preset criteria.

Decision-makers need to have a better understanding of the roleof metrology and the need of assigning to it the appropriateresources; in developing countries this means defining needs andfinancial sources.

With the goal of offering the expected services within availableresources, the national laboratory or institute of metrology, thelegal metrology organisation, and the accreditation system requireplanning. A careful inventory of the needs in all areas is thusmandatory. It should be done, not only from the point of view ofthe type of instruments and their required precision, but also inregard to the annual number of verifications and their geographicaldistribution keeping in mind that quite a number of instruments

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General aspects

that require regular verification cannot be easily transported tothe central laboratory. The number of instruments to be subject tolegal control must be estimated for each category.

A fact that should not be overlooked is that, whatever the initialcost of implementing a metrology laboratory, in the long run thehighest impact on its budget will be for qualified personnel andoperation costs.

In large companies, investments towards good metrologicalpractice are easily amortized; in small and medium sizedcompanies they can become an important component of costs.The more so in countries that do not have a metrologicalinfrastructure and where, as a consequence, this cost cannegatively influence competitiveness.

A developing country is advised (79) to base its planning of officialmetrological facilities on a scheme that should include, in a slightlyhigher measure, metrological supervision based on verificationof instruments that would not be subject to control in developedcountries.

1.5. Study of the situation of legal metrology in the country

There are two roads for the study of the situation and the needsfor legal metrology: a study of the legal framework or theidentification of elements subject to legal metrology.

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1.5.1. Study of the legal framework of metrology

What is done here is an analytical study of all legal elementsapplicable to quantity measurements; it can be based on thefollowing diagram.

Legal framework of metrology

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General aspects

1.5.2. Identification of elements subject to quantitymeasurements

In this option, the analysis is done on the elements that aresubject of quantity measurement, according to the differentbranches of economic activity.

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2. Basic concepts

Legal metrology works with several elements whosemeaning must be clearly understood.

We will be using the following:

- metrology,- legal metrology,- type or model approval,- verification,- certification,- accreditation,- SI units,- calibration,- traceability,- intercomparisons,- penalties,- metrological evaluation,- maintenance,- conformity assessment,- control of prepackages,- metrological control,- market surveillance.

In metrology, as in any human activity where information isexchanged through communication, words should not only beknown to all parties, they must also have the same meaning forall. Because we are in a new field, with its own techniques and itsown vocabulary, it is convenient to go through some of the terms

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that will be used even if they are explained in more detail later onin the text. Rather than simple definitions, we try to make clearwhat is understood by specialists for each term; wheneverpossible, we have used internationally accepted definitions (34,103)

or those used by organisations internationally recognised inmetrology.

2.1. Metrology

Metrology is the science of measurements.

Metrology involves all aspects, theoretical and practical, ofmeasurements independently of their uncertainties and in all fieldsof science and technology.

Particularly, it has to do with:

- the theory of measurements,- the measurement units and their physical realisation,- the methods and procedures of measurements,- the characteristics of measuring instruments,- people and organisations involved in measurements.

2.2. Legal Metrology

There are several definitions of legal metrology, formal andinformal, which are not contradictory although they differ slightly:

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Basic concepts

The International Organisation of Legal Metrology, OIML, on itsInternet web page, tells us that: legal metrology is the entirety ofthe legislative, administrative and technical proceduresestablished by, or by reference to public authorities, andimplemented on their behalf in order to specify and to ensure, ina regulatory or contractual manner, the appropriate quality andcredibility of measurement related to official controls, trade, health,safety and the environment.

The International Vocabulary of Terms in Legal Metrology,published by OIML itself (34), defines legal metrology as that partof metrology relating to activities which result from statutoryrequirements and concern measurement, units of measurement,measuring instruments and methods of measurement and whichare performed by competent bodies.

The Academy of Sciences of the Institut de France (9), establishesthat legal metrology, the modern form of weights and measurescontrol, is the activity through which the State decides to takeregulatory action over certain categories of measuring instruments(those used for commercial transactions) or over certainmeasurement procedures (public health, public safety,environmental protection).

For the Physikalisch-Technische Bundesanstalt, PTB, in Germany(21): metrology controlled and regulated by State resolutions isqualified as “legal metrology”. Legal metrology covers those areaswhere there is a special public interest for correctness inmeasuring devices and the corresponding values. These areas

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cover all official measurements carried out, for instance, forcustoms and taxes matters or traffic surveillance or, particularly,commercial transactions that involve weighing devices, electricmeters, instruments to measure liquids, etc. It also looks afteraspects related to health and environment protection.

To some people, legal metrology is that part of metrology whichacts when there are possibilities for conflict, specially when thedamaged party does not have the possibilities or the expertise toevaluate the measurement results.

2.3. Type or model approval

What is known as type or model approval consists basically ofjudging if a particular type or model of measuring instrument isadequate to carry out the functions for which it has been designedand manufactured.

Model approval can be applied to instruments that, by law, requiremandatory verification, or it can be done at the request of themanufacturer.

The purpose of the tests is to find out if the instrument will probablycomply with the requirements set for its correctness and reliabilityduring the validity period specified in the verification.

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Basic concepts

2.4. Verification

The terms verification and certification are not always used withthe same sense in all countries. Because of its clarity, we preferthe meaning as used by PTB in Germany and we will be using itfrom now on in this document.

Verification of an instrument or of a materialised measure consistsof technical tests carried out according to regulations by acompetent authority, and of the corresponding markings.

By a materialised measure we mean a device intended toreproduce or supply, in a permanent manner during its use, oneor more known values of a given quantity. Examples ofmaterialised measures are weights, a standard electric resistor,and a reference material in chemistry.

Verification is a preventive measure by which instruments areexamined to see if they comply with the characteristics of theapproved model and with the prescribed error limits.

By means of verification, the competent metrological authoritiesensure that the instruments are adequate and the measurementscorrect. It brings confidence in independent and supervisedexaminations as well as in protection from manipulations oncethe instrument has been examined. One of the main tasks of legalmetrology is to see that citizens can be confident of the correctnessof measuring instruments.

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The duration of validity for verification is normally limited so thoseinstruments must have markings indicating the expiration date ofthe verification.

There are systems for verifications subsequent to the initialverification and they take into account the type of instrument understudy.

2.5. Certification

Certification differs from verification in that an accredited centreor laboratory does the official tests.

2.6. Accreditation

According to the Inter American Accreditation Co-operation, IAAC,accreditation is the procedure by which a recognised authority inthe subject gives formal recognition to a person or institution abouttheir competence to carry out a specific task.

Accredited centres can be associated to manufacturers or publicservices organisations. In all cases, the accredited centres areinspected at regular intervals by the accreditation body.

Even when accredited bodies are private companies, from themoment they accept delegation of given powers from the State,they represent State interests.

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Basic concepts

2.7. SI units

A unit of measurement is a particular quantity, defined and adoptedby convention, with which other quantities of the same kind arecompared in order to express their magnitudes relative to thatquantity.

In particular, the General Conference on Weights and Measures(Conférence Générale des Poids et Mesures, CGPM) sets theunits of the International System of Units, SI. This is a body thatgroups all countries signatory of the International Convention ofthe Metre Treaty - also known as the Metre Convention - and thathas been active since 1875, presently with 51 State Membersand 16 Associated States.

Measurements must be expressed in terms of units such thatresults can be repeatable at a long range and will be coherentwith other measurements done in any field of science andtechnology. Because of these requirements, base units are nolonger based on artifacts (with the current exception of thekilogram) but rather on the physical constants known asfundamental.

Currently, the SI system is used almost universally in trade, scienceand technology. Even in the United States of America, consideredby some as the last bastion of the pound-foot-second system,there is a trend towards gradual adoption of the SI.

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When users do not have their own means of doing directmaterialisation of units, practical application of the SI is donethrough a national system based on materialised units, kept at anational laboratory of metrology that is usually the national bodyfor scientific metrology.

2.8. Calibration

Calibration (103) is the set of operations that establish, underspecified conditions, the relationship between value of quantitiesindicated by a measuring instrument or measuring system, orvalues represented by a material measure or a reference material,and the corresponding values realised by standards. These valuesrealised by standards are commonly understood to be the true(conventional) values attributed to the standards and equipmentused as reference during calibration.

The calibration certificate includes data of the results of thecalibration and is a guarantee, when so stated, that the calibratedmeasuring instrument can be traced to national measurementstandards.

2.9. Traceability

Traceability is understood to be the property of the result of ameasurement or the value of a standard whereby it can be relatedto stated references, usually national or international standards,

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Basic concepts

through an unbroken chain of comparisons all having stateduncertainties.

Put more simply, measuring instruments are evaluated againstgiven working standards to determine they are within acceptedlimits of accuracy; these working standards are evaluated againstnational standards that are the determinant standards at thenational level and which, in turn, are evaluated againstinternational standards to make sure that measurements will beinternationally valid. Throughout this chain, the characteristics ofthe instruments are determined and documented.

2.10. Intercomparisons

Intercomparisons are done mostly, but not exclusively, in the fieldof chemical and biological analysis. The involved laboratories dothe same determination or receive an equivalent sample for itsanalysis, and the results of all laboratories are compared. Withthis system it becomes possible to identify common errors withthe same technique, to determine which laboratories carry outanalytical procedures that give consistent results, and to evaluatereference materials. When there are difficulties for calibration,such as in the field of telecommunications (10), laboratoryintercomparisons are an alternative to calibration systems.

If standards calibration and verification of measuring instrumentsis a vertical hierarchical structure, intercomparisons can be seenas a horizontal structure that can complement or substitute the

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use of national standards. It is through intercomparisons that it ispossible to reach Mutual Recognition Agreements/Arrangements,commonly called MRAs. With these agreements, an instrument,a measurement procedure, a measurement result, accepted inone of the countries signatory of the MRA, is also valid in theother signatory countries; this avoids costly and troublesomerepetitions of tests such as when, for example, those tests are arequirement for commercial transactions between the countriesof the agreement.

2.11. Penalties

It is a function of legal metrology to see to the observance of lawsand regulations that are somehow related to measurements; thus,it also has to decide what to do when these laws and regulationsare not observed.

This can be the case when electricity or water meters have beenintentionally manipulated to give wrong readings, as well asalterations in records, documents, stamps or labels of measuringinstruments.

Pre-packaged products where the correct amount is not filled inor declared properly or whose presentation and labelling aremisrepresentations, are also considered a punishable offence.

Normal practice is to put in place a penalty system that willdiscourage such practices.

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2.12. Metrological evaluation

We will call metrological evaluation a verification requested by aperson who has substantiated doubts about the correctness of ameasuring instrument, and that is done, either by the verificationauthority or by an accredited body under direct supervision of theaccreditation authority.

Metrological evaluation is most often requested for electricity, gas,heat, and water meters.

In Germany, as an example, if the instrument is correct, the personwho requested the metrological evaluation has to bear allexpenses. If, on the other hand, the instrument is shown not tobe working correctly, the applicant does not have to pay forexpenses and may even claim damage compensatory payments.

2.13. Maintenance

Sometimes, correctness of a measuring instrument can beguaranteed only if the instrument undergoes regular maintenancesuch as repairs, changes of components or units, or adjustments.In such cases, maintenance can substitute secondary verifications.

To have the validity of a verification, the maintenance has to bedone by maintenance services that are officially recognised,authorised and supervised by the competent authorities, and usingstandards traceable to a national standard.

Basic concepts

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2.14. Conformity assessment

In the European Union, responsibility for the correctness ofinstruments can be delegated by the State to the manufacturer,by means of conformity assessment, applicable in the regulatedand in the non-regulated field.

In fact, it is perceived that verification by a competent authoritywill be replaced more and more by conformity assessment testsdone by the manufacturer. The State will work less on testingmeasuring instruments and more on the control of the qualitysystems of the manufacturer so that the conformity tests itperforms can have the required legal validity.

2.15. Control of pre-packaged products

When speaking of pre-packaged products we refer to all productsthat are not subject to a measurement at the time of thecommercial transaction. An obvious example is that of allpackaged products sold in shops or supermarkets: bottled oil,flour in packages, dairy products, canned sardines, cereals inboxes, marmalades, toothpaste, cosmetics, cleaning products,etc. But the term can also be applied to medicines, paints, cement,barbed wire, fertilisers, pesticides … the list could be very long.

With pre-packaged products, the controls seek to guarantee thatthe buyer will in fact receive the quantity that is written down on

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the package, within certain limits that are set according to theproduct and to the type of package.

This control can be done at the factories where the product isbeing packaged or by samples taken at several different sellingpoints.

2.16. Metrological control

Metrological control can include:

- design and type approval,- initial verification,- verification after repairs or modifications,- periodic verification,- surveillance and inspection.

The State sets up metrological control to watch over thecorrectness and accuracy of measurements; to assist the healthand safety of citizens through control of biomedical instruments;to avoid frauds damaging to the consumers, with special attentionpaid to the metrological control of pre-packaged products.

Basic concepts

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2.17. Market surveillance

To some legal metrology enforcers, market surveillance is focusednot so much on the models or types of instruments but on theinspection of the individual instruments that are in use.

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3. Scope and impact of legal metrology

Legal metrology comprises all official rulings and it acts bymeans of the proper bodies to enforce laws related tomeasurements. In particular, it has to make sure that:

- the units are of common use, in accordance withnational and international rules,

- the corresponding standards are properly kept,- the types of measuring instruments in use are of

officially approved types or models,- the measuring instruments are verified at preset

periods,- the bodies in charge of control actions are properly

accredited and they carry out their duties underproper supervision,

- measuring instruments and devices in use in thecountry comply with current legal regulations,

- previously packaged products sold on the marketcomply with regulations on quantity or number of theircontents.

Impact of legal metrology may be felt in commerce, in thehealth and safety of persons, the preservation of theenvironment and in the behaviour of producers of goodsand services.

Legal metrology addresses the assurance of the quality of quantitymeasurements through control of the instruments and proceduresused in measurements.

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It originated in the need for fair trade but then evolved towardsother applications of metrology, such as public health and safetyand protection of the environment. Many countries also regulateother aspects of metrology - traceability to national standards isone example - so that these aspects also fall within the scope oflegal metrology.

Usually, legal metrology is implemented by means of generalapplication regulations but it can also appear in contracts signedby a limited number of parties.

It mainly applies to measuring instruments by specifying theirperformance requirements and the procedures for their use andverification; it can also be applied to measurement results byspecifying accuracy and acceptance requirements.

It should be stressed that there is no single model for theapplication of legal metrology; it will depend on the political andlegal structure of each country, its social and economic conditions,and its environment. For instance, during recent years, countriesof the European Union have had to modify their legislation andadministration of legal metrology in the light of the directives ofthe European Union. Later we will go into this in more detail.

Legal metrology is a modern, enlarged form of the control ofweights and measures. It is the activity by which the Stateintervenes through regulations on a given category of measuringinstruments (mainly those used for commercial transactions) or

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Scope and impact

on certain measuring operations (related to public health, publicsafety, and environmental protection).

It extends in several directions:

- the quality of instruments used in commercial transactionswith the purpose of ensuring reliability of measurement andavoid fraud; it is a tool of economic regulation,

- it also works in function of the State by ensuring that statecontrols are safe, fair and effective,

- it helps the productive sector to be able to use reliablemeasuring instruments according to its needs.

We should make it clear that the term “measuring instrumentsused in commercial transactions” has today a very wide meaningand includes such aspects as traffic control (radar in roads,speedometers on trucks and public transport) or public health(thermometers and scales for medical use, blood pressuredevices).

Generally speaking, there are three major situations where controlis carried out:

- when the measuring instrument is designed, by designapproval,

- when the measuring instrument is manufactured and sold,with conformity assessment or primary verification,

- while the instrument is in use, by periodic verifications.

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We can also differentiate two types of metrological activities. Thefirst is to investigate and verify equipment used in commercialmeasurements, and can be considered a mechanical metrologicalactivity. The second looks to the uses of this equipment andincludes all supervision activities.

In mechanical activities it is the duty of the metrologists to inspectand compare with the measurement standards, at regularintervals, all measuring instruments and devices used incommercial transactions in their jurisdiction.

Supervision includes such activities as verification of goods storedfor sale or pre-packaged, verification of cargo in products sold inbulk (fuels, sand, gravel and others), investigation of denunciationsof unfair practices, education of buyers as to their rights andobligations in accordance with metrological laws.

Normally, what we have called mechanical activity should haveprecedence over supervision – without proper and correctequipment a trader cannot be asked to use the instrumentscorrectly. However, it is advisable not to forego all supervision infavour of mechanical activities (46).

This does not mean that the organisation in charge of legalmetrology has to be responsible for all these tasks.

In fact, many countries have ministries or secretariats with directresponsibilities in trade, health, justice, customs, environment,etc. where many activities are carried out that fall within the field

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of action of legal metrology; this often is not seen clearly and thenecessary co-ordination does not exist between the differentinvolved parties, a fact which does not make for a sound, coherentdevelopment of legal metrology.

3.1. Official rulings

Ideally, the study of the legal framework for metrology should startwith a reading of the Constitution or Charter of the State; thetitles or chapters will show which are the government bodies andthe laws that regulate the functions of each of them.

The text of the laws themselves will show the institutions in chargeof specific tasks as well as indications of the regulations that makeoperative both these laws and these institutions.

A perusal of laws and regulations will show the general structureof government and from this it is possible to infer the structures ofruling activities which involve quantity measurements.

As we are interested in the institutional and operative profile ofmetrology, this revision identifies the government entities in chargeof the different aspects of quantity measurements.

Identification of metrology related institutions and laws gives ageneral mapping. To show coherently the legal framework ofmetrology it is necessary to classify by subjects all informationthat is contained in this map.

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Let us for instance suppose that the Constitution establishes thathealth is a function of the Executive branch and that it assigns itto a Ministry or Secretariat of Public Health; this, in turn, is ruledby a law and its regulations. Complementary laws and regulationswill specify activities such as for example hospital affairs, foodcontrol, epidemics control, etc. and the study will show whichentities are in charge of which specific activities, which quantitymeasurements should be made, to what products and services,and how. Regulations will include specifications, measurementstandards, procedures, conventions, etc.

Let us look at another field, Communications and Construction,hypothetically assigned by the fundamental laws to a Ministry orSecretariat of Communications. The mapping of activities derivedfrom the founding law and its bylaws of such a Ministry as well asthe complementary laws and their bylaws, will show matters ofcommunication having to do with physical transport (roads, roadtransport vehicles, railroads, sea and river harbours, airports, etc.),with construction (locations, designs, materials such as concreteand steel, etc.), with telecommunications. Each of these activitieswill probably be ruled by specific laws and their bylaws and willimply, directly or indirectly, measurements and their control. Forinstance, in the field of telecommunications there are currentlydiscussions, at the Western hemispheric level, for theharmonisation of a set of matters having to do with standardisation,certification procedures, and mutual recognition agreements (10).

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The role of Government in metrology can be defined as theobligation to ensure the existence and correct operation of anational system that will basically include:

- acceptance and definition of measurements units to preventthe use of incompatible units,

- maintenance of national measurement standards for the baseunits, with the proper traceability to international standards,

- organisation of the chain of traceability between measurementprocedures and measurement standards, both national andinternational,

- establishment of legal metrology with its diverse functions,- establishment of accreditation systems for metrology

laboratories,- participation in research, training and information on metrology.

In the particular case of legal metrology, legal control is exertedon all devices that measure quantities in commercial transactionsor in aspects related to public health and safety or the environment.These devices can be inspected either individually or on samplestaken by statistical analysis on homogeneous lots.

Legal metrology considers that a measuring instrument complieswith legal regulations if the value it shows is less or equal to themaximum permissible error when the verification test is done bya verification body, under standard conditions and the uncertainty,at a probability level of 95%, is small compared to the prescribederror limit.

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It should be stressed that, if scientific metrology seeks ameasurement as accurate as possible, legal metrology seeks thatthe measurement be as accurate as necessary.

3.1.1. Maintenance of measurement standards and transfer of units

National measurement standards are normally subject to an initialcalibration, at the national metrology laboratory of the countrywhere they were manufactured or, occasionally, at the BIPM(Bureau International des Poids et Mesures).

The body responsible for maintenance of the standards must makesure that they are kept and used correctly.

Need for a new calibration can be determined by:

- the accuracy required by the country,- possible changes in time in the value of the standard, due to

local atmospheric conditions,- possible or suspected changes in the value of the standard

due to its use.

The legal metrology authority is also responsible for the transferof the units, materialised in the national measurement standards,to the complete chain of reference standards and workingstandards so that any measurement may be traced to the

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corresponding national standard and, thus, to internationalstandards.

3.1.2. Type or model approval

Type approval of measuring instruments is done on both locallymanufactured instruments and on imported instruments. It is afirst preventive measure, taken by the Government, to protectcitizens from the effects of incorrect measurements.

Type approval is an administrative act whereby the measuringinstruments subject to mandatory verification are approved fornational verification (or in its case primary regional verification) atrequest of the manufacturer.

Normally, the measuring instruments subject to mandatoryverification are those used in commercial transactions, officialaffairs, traffic, manufacture and analysis of medicines,occupational and environmental safety, medical measurements.

The tests are done to determine if the instruments can be expectedto comply with the set requirements of accuracy and reliabilityduring the validity period specified for the verification. An importantcriterion for the test is the resistance of the measuring instrumentto environmental influences such as temperature, humidity,vibrations, and electromagnetic fields. Also, the instruments mustbe sufficiently protected against falsifications of the measurementvalues through handling errors or intentional manipulations.

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Once the tests are successfully completed, the manufacturerreceives an approval certificate, with the approval marking thatmust be placed, in a clearly visible place, on all measuringinstruments of that particular model.

The granted approval represents a confirmation of quality and isan important factor in the sale of the instruments.

Presently, in Europe, measuring instruments that have been type-approved and verified in one of the states of the European Union,may be imported and used in any other member state withoutbeing re-examined.

Also in Europe, if a Directive of the European Union for a categoryof measuring instruments exists, reference is made to it so thatthe Directive will be transferred into national law.

An OIML Certificate System was established in 1991, for issuingcertificates for types of instruments which fully meet therequirements of the relevant Recommendations and which havebeen tested according to the procedures described in theseRecommendations.

It is also possible to have what we might call a “disapproval” of atype, when law prohibits use of a given model of measuringinstrument. As an example, a decree published in Uruguay in1994 forbids use, starting in 1995, of scales known as “básculade pilón” and the corresponding authorities have been grantedfaculties to seize and destroy such instruments.

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3.1.3. Controls (verifications, certifications, conformityassessment, etc.)

When a type has been approved, the instruments can be placedon the market. Individual instruments of the approved type areverified by the verification authorities or certified when thisverification is delegated to an accredited body.

The measuring instrument is examined to see if it conforms tothe corresponding regulations or ordinances and if it complieswith the type requirements and approval. The most importantcriterion is usually the observance of permissible maximum errorsas set down on the regulations.

Accuracy of a measuring instrument may change over timecaused, for instance, by wear or age. For this reason, the validityduration is limited and reflects the type of instrument. As anexample, in Germany verification of taximeters has validityduration of one year, countertop scales and fuel pumps in gasstations of two years, water and electricity meters of 6 and 16years respectively and both can be further extended.

For extension of the verification validity when dealing withmeasuring instruments which are installed in large numbers suchas gas meters, water meters, electricity meters, a test by samplingmay be done instead of a secondary verification. This methodcan reduce considerably the testing costs for the supplyingcompanies.

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Again in Germany, gas, water, electricity and heat meters areverified in testing centres officially recognised by the State. Mostof these centres are located at the companies supplying water orelectricity or in some of the companies that manufacture theseinstruments. Correctness of the testing procedures is guaranteedby the use of measuring devices tested at the PTB and by themetrological control of the testing centres carried out regularly bythe verification authorities.

All these services are subject to specific fees.

When the manufacturer of the measuring instrument doesverification we speak of conformity declaration or conformitytesting. In this case, it is the manufacturer himself who certifiesthat his measuring instruments conform to the type approval. Thecompany must usually have in place a quality system that complieswith the requirements of regional or international standards andthis quality system is supervised periodically.

Subsequent verifications may be substituted by maintenance orby comparison measurements done by qualified operators.

This way of proceeding is being used more and more in Europe,to transfer to the manufacturer the responsibility for the correctnessof the measuring instruments.

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3.1.4. Supervision of organisations in charge of specificcontrol activities

Concrete forms of metrological supervision must take into accountthe economic system of the country, the organisation of its legalsystem, its territorial organisation, and other features and specificconditions.

Use of computer controlled measuring instruments with functionslargely determined by software will require new methods for initialand subsequent verification.

It is probable that in the future conformity testing by themanufacturer of the measuring instruments will become morecommon. This will result in a shift in the tasks of the verificationauthorities; they will perform fewer testing activities but they willhave to increase their supervision of manufacturers.

In some countries, such as Colombia (97), it is “mandatory to havecalibration laboratories accredited by the Superintendent ofIndustry and Commerce at all companies supplying domiciliarypublic services in which measurements are required for billing,and these companies shall also have their measuring instrumentperiodically qualified”.

Now, there can be conflicts of interest when a supplier ormanufacturer is in charge of verification tasks and this is why astrong and effective supervision is necessary.

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To determine if a measuring instrument is working properly is notnecessarily a task for the user. The subsequent verifications arestill the responsibility of the metrology authorities as are also thesupervision of certification bodies, or the maintenance and repairwith a consequent certification.

3.1.5. Accreditations

Accreditation is the formal recognition that a certification orinspection organisation, or a testing or metrology laboratory, hasthe required technical competence and fitness to carry out thosespecific functions for which accreditation has been granted.

Accreditation is a guarantee for the user that the accredited bodyis independent and competent and that its services are renderedeffectively in terms of time and cost.

Accreditation organisations, on their part, are subject to regularsurveillance by a body with the required authority, frequently agovernment body.

Laboratory accreditation is a way of determining that a laboratoryhas the required competence to carry out specific tasks of tests,measurements or calibrations. Whoever needs to check orcalibrate a product, a material or an instrument, can thus have areliable source. The laboratory itself can determine if it is workingcorrectly, under the appropriate standards. Manufacturers can alsouse laboratory accreditation to make sure that the tests doneinternally on their products are correct.

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Adoption of the international guide ISO/IEC 17025 ensures auniform way of determining the competence of a laboratory and itpermits international agreements for the recognition ofaccreditation systems.

3.1.6. Market surveillance

By market surveillance we understand the determination of thegeneralised compliance of the relevant regulations by individualmeasuring instruments.

The European Union(23) considers the purpose of marketsurveillance to be the guarantee of compliance with the resolutionscontained in the directives applicable to all member countries.Citizens are entitled to an equivalent level of protection in thewhole Single Market, independently of the origin of the product.Market surveillance is also of importance for the interests ofeconomic agents as it helps to eliminate unfair competition.

To the Europeans, market surveillance has two main aspects:

- national surveillance authorities must supervise that marketedproducts comply with national laws that have transposed theNew Approach directives, and

- later, and as required, they must adopt measures to ensureconformity.

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From the point of view of legal metrology, surveillance measuresapplied to manufacturers, importers, traders, maintenanceservices, repair services and users, have as their goal to guaranteethat the measuring instruments conform to requirements, that theyare tested and marked according to regulations, and that theyare used properly.

Ignorance of the law is an unacceptable excuse for not complyingwith it. The owner of the instrument is responsible for havingregular servicing that will maintain its operating capacity withinprescribed tolerances in compliance with applicable specifications.

Similarly, a packager must use accurate standards to makeadjustments to his packaging equipment and he must have aquality control system that will keep individual variations inpackages within acceptable limits so that the average weight ofthe product will comply with the declaration of quantity.

Market surveillance should ensure that all measuring instrumentssubject to verification are verified and it should be done under thedirect supervision of authorities (100).

One thing to keep in mind is that the main purpose of legalmetrology is not to make money. It includes technical andsurveillance tasks and it is usual for the technical services togenerate income that can then be used to cover the expenses ofsurveillance; this, in fact, is an argument sometimes used againsttotal privatisation of legal metrology services.

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3.1.7. Control of pre-packaged products

In legal metrology, pre-packaged (or pre-measured, orconditioned) products, often called pre-packages, are thoseproducts that are packed in packages of different types, formsand sizes and closed before they reach the consumer. In thesepackages the quantity of product contained cannot vary unlessthe package is opened or considerably altered.

Pre-packages must be clearly labelled with information on theircontents in terms of quantities, whether mass, volume, length,area, or number of units. The packages must be so designed thatthey do not appear to contain more of the product than they reallydo, a practice known as deceptive packaging.

As measuring instruments become less used in direct sales toconsumers, verification of pre-packages is gaining in importance.

Regulations concerning labelling of pre-packages specifyrequirements that at least the following items should appearclearly:

- the identity of the product,- the name and address of the manufacturer, packer, distributor

or importer,- the net quantity of product, according to the type or product

and its presentation,

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the types and sizes of letters and numbers to indicate contentsare also specified.

This does not preclude other labelling requirements such asnutrition facts in food products or warnings in products that canbe dangerous.

For technical reasons, it is now very common for pre-packagesverification to be done instead of the verification of packagingunits and equipment.

For this purpose, tests are done, based on statistical sampling,usually at the packaging facilities. Criteria such as the followingare commonly applied:

- the average content of the packages must be equal to, orgreater than, the nominal quantity,

- only 2% of the tested packages can be below the first tolerancelimit, TL1,

- no package can be below the second tolerance limit, TL2.

This control can be done at the factories where the product isbeing packaged or by samples taken at several different sellingpoints.

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So far, we have been looking at legal metrology from the point ofview of its functions; let us now review briefly its impact on theactivities over which it acts by law.

3.2. Commerce

The citizen seen as a client in the retail trade is possibly the personmost often associated with legal metrology. And in fact, the impactof a few grams per person in each commercial transaction canbecome many kilograms when these transactions are added up.

Weighing devices in all their forms are among the measuringinstruments most often used in commercial transactions. Modernsupermarkets use electronic scales, sometimes for self-serviceby the client, that can be part of a combined system and areconnected to the cash desk and the central computer.

These systems of measuring instruments connected to cash desksas they are used in retail trade must comply with the samerequirements as those of any equivalent measuring instrument.

With pre-packages such as sugar, flour, canned beverages, milk,etc., the client is not able to follow the measuring process duringpackaging of the product. For this reason, verification authoritieshave to verify the content of the packages according to therequirements of the regulations for pre-packaged products.

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Other important items of the domestic budget are filling the fueltank of a vehicle, buying liquefied gas for domestic use, and thepayment of public services such as water and electricity.

3.3. Health

When legal metrology is at work in the field of health one thinksimmediately of verification and control of apparatus such as:clinical monitors, medical thermometers, blood pressure devices,electrocardiographs, devices to measure pulse rhythms,audiometers, etc.

There are more dramatic situations when there are problemsderived from an excessively high or too low a dose of therapeuticradiation that can cause death or an insufficient treatment of thedisease. The frequency of controls will depend on the extent ofthe danger that an incorrect function of the instrument wouldrepresent for a patient.

But there are also less obvious situations where a correctmeasurement can impact health. For example, correctdetermination of the levels of deafness to approve retirement of aworker or the control and regulation of noise now its long-rangenegative effects are known. In some cities (58), granting of a licensefor a certain type of business, restaurants for instance, isconditioned to their having adequate protection to prevent noisefrom being a nuisance to their neighbours.

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The effect can sometimes be indirect as with the correctdetermination of aflatoxins in feeds given that their metabolite(M1 aflatoxin) will be present in milk; in European Union countries,powdered milk has limits of 0,01 mg l-1 of M1 aflatoxin as well astraces of heavy metals such as cadmium, lead and mercury (90).This also shows that incorrect measurements can result in aproduct being rejected for import because it does not comply withquality requirements.

In Europe, starting January 1st 1995, European Directives havebeen transformed into national law. A medical measuringinstrument can be marketed or put in use only if it conforms to therequirements of the law on medical devices and if it carries theCE marking.

Currently under discussion are international regulations that willrule food labelling and ingredients derived from geneticallymodified organisms, an aspect over which there are differencesof opinion between several countries.

3.4. Safety

To contribute to public safety, legal metrology acts over severalsectors.

One of these is road traffic. Everything that is related to correctadjustment of vehicles (tire pressure, motor performance, drivingsystem, braking system, electrical system, emergency signals)

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requires some type of measuring instrument. In some States ofthe United States of America, a used car must undergo aninspection before it can be put on sale. When speaking of publicroad transport we have to add the weighbridges to determinepotential overloads that can cause accidents. Traffic lights (redlights) must be synchronised. Measuring instruments used by thepolice, such as alcoholmeters to measure the amount of alcoholin the blood or speed meters for speed control on roads and onstreets, also require periodic verification. We can also mentioncontrol of the operating conditions of cargo and passengeraeroplanes, weighing of cargo and baggage, instruments in theair traffic control towers.

Safety in the working place also demands measurements thatare directly or indirectly verified through the system of legalmetrology. To be approved and given maintenance, personal orcollective safety equipment such as protectors, barriers, specialclothing, smoke detectors, fire extinguishers, emergency exits,etc. must conform to standards, and verification of compliancewith these standards requires diverse measurements.

3.5. Environment

Everyone is exposed in a greater or lesser degree to pollutantsthat are not only annoying but can be detrimental to health. Onthe other hand, it makes no sense to limit by law these pollutantsif they cannot be measured correctly. A correct measurement is

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essential when the result can be the basis for a decision taken bya court of law or an authority.

In modern life we are all subject to pollution by:

- exhaust gases and soot from vehicles,- radiation from nuclear medicine applications and handling of

the equipment,- noise from traffic or at the working place or in the vicinity of

airports and railroads,- waste waters not properly treated,- pollution of drinking water, of rivers and seas, by cleaning

agents and solvents, and its impact on the fauna,- soil pollution and the resulting effects on agriculture in terms

of health and economics,- high radon concentrations in basements and underground

parking lots,- excessive ultraviolet radiation, particularly in the tropics, from

damage to the ozone layer or from soldering work,- low frequency electromagnetic fields when operating electrical

appliances or by high-frequency broadcasting.

Pilots and air traffic controllers, interpreters and sound engineers,are prone to suffer occupational diseases caused by the noiselevel to which they are exposed. With the current availability ofportable sound apparatus and mobile phones, there are everydaymore persons exposed to excessively loud noise.

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3.6. Development of enterprises

We must keep in mind that both as consumer and as businessman,every person has the right to be protected against incorrectmeasurements.

Metrology supports national industry by making available atechnical basis, with the right accuracy for its needs, to calibrate,check and verify its measuring and control instruments and byguaranteeing calibration of measuring instruments and equipmentat industrial testing and assay laboratories. It can also providereference materials duly homologated and certified forautocalibration of equipment and it can also carry out studies,tests, assays and special measurements, determination ofphysical constants, at the request of government or privateorganisations as well as giving technical assistance on industrialmeasurement problems.

In industry, legal metrology acts on instruments such as callipers,micrometers, comparison clocks, gauge blocks, micrometers,pressure gauges, industrial thermometers, thermocouples,pyrometers, analytical scales, etc. as well as assay instruments,chemical analysers and many more.

There are private companies that supply public services such aselectricity, gas, heat, and water to homes, industries and otherconcerns.

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The farmer uses the right type of scale for cereals or cattle, liquidor volume measures for milk, butirometers to determine thecontent of fat in milk; in cereals, humidity and apparent bulk loaddensity are important criteria.

Quality of cement is important both for the solidity of a buildingand for the price of concrete and in construction the relativequantities of materials must be carefully measured.

Measuring instruments are used to determine properties ofcomponents and of manufactured products and they are becomingcommon to control, regulate, automate and monitor processes.Measurements are used to verify manufacturing tolerances andfunctional reliability of the products. They have become animportant component of quality assurance.

Industry needs measurements of force, pressure, vacuum, flow,length, areas and volumes, angles, gears and cylinders,roughness, temperatures, viscosity, density, DC and AC current,high frequencies, time, reference materials for magnetic datamedia, ionising radiation, etc.

A legal metrology system, with a sound metrology infrastructure,can be of great help to industry by making accessible such servicesas calibration and verification, standards and reference materials,with the confidence that such services follow internationalstandards and regulations and can thus contribute to thecompetitiveness of local enterprises.

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4. Legal metrology in the juridical system of a country

Metrology laws are not the same in all countries becausethey must agree with the national legal structure. In legalmetrology the involved parties, with specific responsibilities,and whether integrated or not, are:

- the normative authority,- those responsible for the metrological

infrastructure,- the executive authority,- the supervisory authority,- the penalty authority.

There can be a single general law covering all aspects ofmetrology and/or laws concerning specific aspects suchas a law on legal metrology.

OIML has currently under preparation and discussion adocument containing the essential elements of a law onmetrology; several aspects of this document are includedin this chapter.

We have mentioned before the importance of studying theFundamental Charter or Constitution of the State to know clearlythe different government bodies of the country and the laws rulingthem.

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It is through a study of the laws that it becomes possible to identifyinstitutions in charge of specific tasks, and the study of thecorresponding law’s regulations will identify activities that requirequantity measurements and, thus, the fields where legal metrologyis bound to act within the legal structure - always keeping in mindthat the goals of legal metrology for universal protection can bemet by using both prevention and punishment.

To be also taken into account is the fact that Law is in constantevolution; we can mention as examples the unipersonal societies,condominia, new payment techniques particularly those usingelectronic media, the new available reproduction techniques andtheir impact on intellectual property rights, etc.

In legal metrology, the involved parties, having specificresponsibilities, are:

- the normative authority,- those responsible for the metrological infrastructure,- the executive authority,- the supervisory authority,- the penalty authority.

According to the legal system in each country, theseresponsibilities can be concentrated in a single body or they canbe partially or totally decentralised. One of the difficulties that canarise from decentralisation is that the several entities may beinsufficiently linked among themselves with the result that each

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tries to fulfil its duties without taking into account what the othersare doing.

We will try to make clearer this crucial aspect.

When, for instance, the normative authority is separate from theexecutive authority, it can set out requirements that cannot bemet due to technical or local circumstances. This is the case withsome environmental standards having to do with maximumpermissible limits of dioxin, a chemical whose correct analyticaltesting requires accuracy not available in most laboratories. If thetests cannot be done to support an effective supervision, whatsense is there is approving standards that require those tests?

Another situation arises when those responsible for themetrological infrastructure do not have, by law, the faculty ofimposing penalties. There can be laws setting the officialmeasurement units and the approved measuring instruments but,if there is no functioning system for supervision and penalties totransgressors, these laws will never be more than dead letters.

The authors are familiar with a case where, by law, the legalsystem of units is the SI International System. However, drinkingwater is billed in cubic meters while fuels are sold in gallons. Roaddistances are given in kilometres but building lots are sold bysquare “varas” (slightly smaller than square yards), agriculturalland by “manzana” (around 7 000 m2) or “caballería” (450 000m2), some crop extensions are measured in “cuerdas” (which is alinear measure) while fabrics are bought by the yard but electric

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wire is bought by the metre. In retail trade onions and tomatoesare sold by the pound … and so on.

4.1. The law on metrology, other related laws and resolutions

As could be expected, metrology laws are not identical betweencountries, as they must fit into the national legal structure.

Let us look at a few cases. In Mexico (45), it covers standardisation,accreditation, certification, surveillance, penalties and resources.

In Spain (53), a constitutional mandate assigns to the State theexclusive competence to legislate on weights and measures (theold concept of “weights and measures” being superseded in thenew laws by that of “metrology”) and it also determines officialtime in Spain.

In the United States of America (101) there is no national metrologylaw as such but the States have adopted, among others, acommon law on weights and measures.

Generally speaking, whether it is a single metrology law coveringall aspects, or several related laws, they must take into accountat least the following:

- the legal and authorised measurement units, their physicalrepresentation and their field of application,

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- the national body in charge of custody of the measurementstandards or of the realisation of the units,

- the properties of measuring instruments,- the type of activity that requires legal control of measurements

and of measuring instruments,- aspects of manufacture, sale, repair and maintenance of

measuring instruments,- the type of activity requiring metrological control of the quantity

of product (pre-packaged products are an example),- national bodies in charge of metrological control,- procedures for legal control (type approval, verification stamps

or markings, legal powers),- treatment of transgressions and legal procedures.

These laws and regulations address the general public and thecourts of law and they must be in a language appropriate for thelegal authorities of the country.

As there is usually quite a lapse of time between formulation of alaw and its enactment, the text should not include technicalelements that may be subject to change. For instance, it is betternot to include in the law the scientific definitions of the base unitswhich are better included in an annex, together with possibleconversion tables, while derived units would be better in theregulations of the law.

As to specific laws regarding the several categories of measuringinstruments, it is advisable to follow the OIML International

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Recommendations that are model regulations with aninternationally approved basis.

4.2. The OIML model for a Law on Metrology

The OIML published in 1975 a model law on metrology; thisdocument is currently being revised and updated and it has beenplaced for international discussion under the title Elements for alaw on metrology (62) . It is not yet considered a definitivedocument and it covers all of metrology not exclusively legalmetrology, but as it is put out by the recognised legal metrologyinternational organisation, it is used as the basis, sometimesverbatim, for the rest of this section.

The laws for which the document gives advice may be a generallaw covering all aspects of metrology, as well as laws related tosome specific aspect of metrology, such as a law on legal units, alaw on traceability, a law on legal metrology, etc., or provisionsrelated to metrology in more general laws such as a law onconsumer protection or a law on conformity assessment.

Governmental regulatory responsibilities include health, safetyand environmental law. While these functions are disparate innature, a unifying feature is that compliance with the law dependsupon measurement results. Therefore, the process ofmeasurement is of direct concern to the government. Providingthe laws and regulations, controlling measurement through marketsupervision and/or surveillance and developing the infrastructure

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supporting accuracy of these measurements (e.g. throughtraceability) is essential to fulfilling the government’s role.

The importance of accurate and reliable measurement results isever increasing due to rapid technological development and theemergence of the information society. Consumers must makedecisions every day, based on measurement results, which affecttheir economic and personal well-being, as well as judging theactions and efficiency of public authorities.

Since the manufacturers and sellers of most products control themeasurement process used in trade, buyers (persons as well ascompanies) are at a potential disadvantage regardingmeasurement results and their interpretation. This places buyersin a weak and risky position.

The international community has adopted systems of units,measurement standards and requirements for measuringinstruments through treaty organisations (i.e. the MetreConvention and the OIML). In addition, regional metrologyorganisations are harmonising requirements throughout theirmember economies. The intent of these organisations is tofacilitate trade and exchange of measurement results. Documentsand recommendations published by these organisations are aprimary resource for structuring a national metrologicalinfrastructure.

Adoption of a document, such as a law on legal metrology, mayoccur in one of several ways including:

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- adoption by reference to a specific edition,- adoption by including the verbatim text in the regulations,- adoption by including identical requirements, but no identical

text,- adoption by including compatible but not identical

requirements.

Proposals will have to be considered, selected and adapted byeach country according to the specific needs, then dispatchedamong laws, government acts, ministerial acts, according to theconstitution of the country. For example, the relevant issue relatedto metrology may be included in a single law, or may be distributedin a law on legal units, a law on conformity assessment and a lawon legal metrology.

Several issues are recommended by OIML to be considered in alaw on metrology.

Metrology policy should include:

- definition of units of measurement,- developing, maintaining and disseminating the national

measurement standards and making sure of their internationalcompatibility,

- support to the development of metrological infrastructure,• scientific and technological development,• development of the economy,• protection of consumers and citizens,

- directing and financing of metrology research activities,

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- development of education and training for metrologists,industry and the public,

- development and adoption of metrological regulations,- enforcement of metrological regulations,- assessment of conformity to metrological legal requirements,- informing the public on metrological issues.

Metrological infrastructure means laboratories, certification bodies,training centres, documentation centres, consultancy, regulationsand enforcement, etc. in order to provide the necessary services.

The definition of the legal measurement units, their multiples andsubdivisions, their notation, shall be laid out in national standards.It is recommended to put these definitions in documents adoptedat the most appropriate level to facilitate their updating and toavoid unnecessary details in the acts submitted to the legislationauthorities.

The law will determine the legal measurement units and also theirrealisation and the fact that they are obligatory.

Units other than the legal units may be authorised, in particularwhen they are specified in the standards and their use is justified:

- by the needs of international trade,- when they are used in international standards,- for specific uses such as air or maritime navigation,- for human health,- for customary, household or non-commercial purposes.

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The national measurement standards shall be traceable to theinternational standards or to other recognised national standards,or realise the definition of the legal units. Traceability may beestablished through a national accreditation system or by legalrecognition of traceability to other signatories of the CIPM MRA(Comité International des Poids et Mesures – Mutual RecognitionAgreement).

When a national metrology institute, NMI, is set up by law it hasthe following objectives:

- to establish the national system of units,- to keep and maintain the national measurement standards,- to carry on appropriate intercomparisons to ensure their

international coherence- to direct research work for the improvement of the national

measurement standards- to organise transfer of technologies from research teams to

industry,- to study the needs of society for improving and disseminating

measurements standards,- to be the national reference for the national accreditation

system of calibration laboratories, regarding competencies andmeasurement standards,

- to provide appropriate calibration and measurement servicesto meet the needs of users,

- to advise the government on technical issues in metrology,- to participate in international and regional work,

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- to provide consultancy to the relevant bodies and to the public,on metrological issues and on the importance ofmeasurements,

- to provide and/or organise training for trainers in metrology,for education and improvement training bodies,

- other objectives consistent with the intent of the law.

The NMI shall be impartial and its operating resources can beobtained from several sources:

- subsidies of the government for missions of general interest,- contracts with the government for identified tasks required by

the government,- verification fees for legal control activities,- commercial services,- grants from various organisations.

The NMI – whether public, private or a public co-ordination agency– should be in charge of metrological research and legal metrologytechnical activities, particularly the study of technical requirementsfor new regulations and the type tests and approval.

This NMI can also direct the technical work for the enforcementof legal metrology by:

- the study and propositions for the technical regulatoryrequirements on the different categories of measuringinstruments,

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- issuing national and OIML type approval certificates,- the definition of the recommended equipment and technical

procedures to be applied by the local metrology authorities,- the organisation of technical training for the staff of the central

metrology authority and the local metrology authorities,- the training of legal metrology officials and the establishment

of minimum training and performance requirements to be metby all legal metrology officials,

- the development and dissemination of public educationprograms to support implementation of assignedresponsibilities.

In the particular case of legal metrology, our main interest, thepurpose of the resolutions must be:

- to protect the interests of persons and enterprises,- to protect the interests of the Nation,- to protect public health and safety,- to protect the environment,- to regulate measurements such as:

• sale of products by mass,• temperature conversions for certain transactions on oil

products,• measurement of the actual calorific power of natural gas for

certain transactions,• measurement of surface areas for lots and buildings offered

for sale,• measurement and information of performance of industrial

products (fuel or electrical consumption, noise levels, etc.),

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• measurement and label data on the composition of foodproducts, etc.

- regulations for pre-packaged products,- regulations for measuring instruments.

Legal metrology takes into account:

- punishable offences,- liability of persons and corporate bodies, and infringements,- evidence in prosecution.

The law on metrology must also consider the financial provisions,that is, where will the funds come from and their management.

In some regions, because of treaties, regional texts may havepre-eminence over national laws and regulations. This is the casein the European Union, where European Regulations andEuropean Directives are higher in the hierarchy than national texts.New members must take the necessary measures to ensure that,from the moment of adhesion, they comply with Europeandirectives and decisions.

These regional texts may be of direct application when it is notnecessary to transcribe them into national laws, or of indirectapplication when they have first to be transcribed into nationaltexts.

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The application can be total when national regulations must bestrictly identical to the regional texts or optional when they can bedifferent as long as they are compatible with the regional texts.

From the point of view of metrology authorities, in countries whereinstitutes outside the administration exist and have sufficientcompetencies, the tasks of the administration may be reduced tothe essential actions of enforcement and monitoring. When, onthe other hand, the technical competencies lie in theadministration, it will have to direct the technical activities.

The level of centralisation or decentralisation is an essential issueof the political organisation of the country. In the law on metrology,it will be defined in accordance with the fundamental texts(Constitution), with the political and administrative organisationand with the general policy of the country. These higher principleswill have to guide the delegation of powers and missions in legalmetrology between the central authorities and the local authorities.

Metrology policy should be managed or at least co-ordinated byone single central authority of the country (CMA). It will establishthe regulations to implement the law on metrology and will be incharge of international relations.

Local metrology authorities can be:

- local offices of the ministries, under the authority of the CMA,- services of states in a federal organisation or services

depending on locally elected authorities.

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Their mission must be clearly defined and, when they are notdirectly under the authority of the CMA, the law should includeprovisions to direct the co-ordination by the CMA.

There will be laws, decrees, regulations, and dispositions, relatedto the law on metrology. Examples could be specific aspects onverification, calibration, accreditation, technical regulations, andstandards.

The general law can focus mainly on measurement units,metrology bodies, measurement standards, instruments, andviolations of the law. Other related laws and regulations, proceduremanuals, and the like can focus on such things as: weighinginstruments, weights and their verifications; capacitymeasurement, flow measurement (fuel pumps), length measures,electric energy counters, alcoholmeters, electrocardiographs,emissions of exhaust gases, digital clinical thermometers, digitalsphygmomanometers, pneumatic manometers, labelling, pre-packaged or pre-measured products, labelling of food products,liquefied gas cylinders, cosmetics including aerosols, oil,kerosene, bottles; registers of manufacturers, importers andrepairers of measuring instruments, periodic verifications, feesand tariffs for type approval and for primary and subsequentverifications, technical and administrative procedures.

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5. Administrative aspects

The actions of legal metrology are usuallydispersed among several bodies, official,semiprivate or private, and each country followsits own scheme according to its political andadministrative structure.

We look at aspects of such organisations in someEuropean and American countries and, verybroadly, at the tasks for each type of body involved.

We will then comment on administrativeprocedures and some financial matters such asfees and fines.

Most governments have set up a national legal metrologyorganisation but very often a large number of responsibilities aredelegated to the States or the Municipal governments andpractically limited to commercial aspects. In most Caribbeancountries weights laws and some verification standards wereoriginally with the local police and, in the case of importedmerchandises, with the customs offices.

No matter what its political and administrative structure (federalstates, provinces, prefectures, cantons, municipalities), in severalcountries legal metrology is centralised and there are no local

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verification offices. This is the case for instance in Barbados, CostaRica, Ecuador, Holland, Jordan, Peru, Singapore (42,43).

There are many more governmental bodies that are involved inmetrology, often not explicitly, in areas such as consumerprotection, health, environment, communications, and agriculture.

There is today a tendency towards privatisation and deregulationof legal metrology. This could bring about an increase in thenumber of bodies acting in legal metrology and result in regulationsbeing substituted by other conditions with the consequence ofnon-tariff barriers to trade. This point of view, if it prevails, willrequire a very strong international harmonisation.

5.1. Public authorities involved in legal metrology – some models

This is not a study on the situation of legal metrology in severalcountries; they are mentioned simply to show some of thedifferences and similarities in the administration of legal metrologyin countries with different political and juridical organisations.

Brazil:

In Brazil, the Metrology Institute, INMETRO, is responsible forproposing policies and directives, co-ordinating and supervisinglegal metrology activities in the country, and for the weights and

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measures institutes – state organisations in charge of ensuringcompliance with metrological technical regulations.

Canada:

Measurement Canada, MC, of Industry Canada, is the nationalorganisation for legal metrology and is in charge of local andregional verification. The National Research Council, NRC, is thecustodian of the national measurement standards and isresponsible for the maintenance of reference measurementstandards. Both entities have systems in place for the calibrationand evaluation of measuring instruments.

Chile:

The National Consumer Service (Servicio Nacional delConsumidor) in Chile is in charge of:

- the definition of the measurement units used in the countryand their scope of application,

- the organisations who must verify and approve measuringinstruments and the reference measurement standards,

- the definition of legal procedures in those cases where thelaw is not complied with,

- appointment of the organisations in charge of realisation,custody and dissemination of national measurementstandards,

- the definition of accreditation procedures,

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- specification of procedures for metrological control and controlof pre-packages.

France:

The national metrology office, Bureau national de métrologie,BNM, created in 1969, became at the end of 1994 a group ofpublic interest associating the related five primary laboratoriesand the two ministry departments (Industry and Research, andHigher Education).

The five primary national laboratories in charge of measurementstandards or materialisation equipment are ascribed to fivedifferent organisations:

- the National Metrology Institute (BNM-INM) at theConservatoire National des Arts et Métiers (CNAM); mass (upto one kilogram), length, temperature, acoustics,spectroradiometry, photometry and some derived units;

- the National Testing Laboratory (BNM-LNE) whose primaryactivities are related with amount of matter, several mechanicalunits, mass over one kilogram and derivatives, temperature,radiometry, acoustics;

- the Primary Laboratory for Electricity and Magnetism (BNM-LCIE) in the fields of electricity, magnetism and X-rays;

- the Primary Laboratory of Ionising Radiations (BNM-LPRI) formeasurement of radionuclides activity and dosimetry ofionising radiations

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- the Primary Laboratory for Time and Frequencies (BNM-LPTF)whose activity is centred on frequencies and time.

The chains of measurement standards are managed by theComité Français d’Accréditation, COFRAC, with three traceabilitylevels: primary laboratories, authorised standards centres,authorised metrology services.

According to the French themselves(1) this dispersal in themetrology system results in a lack of visibility, the more so forlegal metrology, distributed among the twenty four research andindustry regional directorates (Directions régionales de l’industrieet de la recherche, DRIRE), increased by the fact that not all ofthem interpret identically the legal texts and that the interestedparty does not always know where to turn to.

Also in France, differently from other countries, legal metrology istotally independent from the National Metrology Office, BNM.

For this reason, the French assert that metrology is one areawhere a reasonable centralisation is preferable, a fact which hasbeen recognised by countries with a federal structure such asGermany or the United States of America.

Legal metrology in France is under the Sous-Direction deMétrologie, at the ministry in charge of industry. This Sous-Direction has several responsibilities:

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- to prepare national legal metrology policy,- to maintain the capacity required to carry out its mandates

and to see it is transferred to the bodies in charge ofimplementation,

- to prepare the regulations having to do with measuringinstruments,

- to represent French legal metrology at international fora,- to co-ordinate and direct all activities related to legal metrology.

On their part, the twenty four DRIRE have the responsibility forcontrol and surveillance of manufacturers, repairers, installers andusers of the measuring instruments in their respective regions,and they must direct the activities of those regional bodies towhich they delegate legal metrology tasks. They must also ensurecoherence and complementarity between legal metrology activitiesand others, particularly technical control and industrialdevelopment.

Some groups in France (1) are of the opinion that, in Europe, thereis a gradual weakening of the role of national legal metrology anda trend towards a European legal metrology.

Germany:

In Germany, legal regulations include the Metrology andVerification Act (Eichgesetz) that is the equivalent of a nationallaw on metrology, ordinances (verification and pre-packages, forinstance) and the Directives of the European Union.

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Responsibilities for legal metrology actions are distributed betweenthe Federation and the Federated States. The Federated States(Länder) are responsible for implementation of regulations, withthe Physikalisch-Technische Bundesanstalt, PTB, as the federalauthority for metrology in Germany.

The PTB:

- sets the basic principles of scientific, technical and legalmetrology,

- carries out supervisory functions harmonisation of metrologyand safety,

- is in charge of the realisation of the legal metrological units,- tests measuring instruments and equipment,- co-operates with technical and legal bodies in matters

pertaining to measurements, standardisation and tests, qualityand safety assurance,

- carries out research and development work in metrology.

Germany has a Committee of the Federated States to advise theFederal Ministry of Economy on matters related to verificationwith possible legal, economic and political consequences.

The German Academy of Metrology trains those who will becarrying out verification tasks.

Many test centres for electricity, gas, water and heat meters areprivate centres, accredited by government organisations on thebasis of ISO requirements.

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Spain:

The Spanish Metrology Centre (Centro Español de Metrología)CEM, created in 1985, is transformed by law, in 1990, into anindependent commercial and industrial organisation with thefollowing functions:

- custody and maintenance of national measurement standards,- setting up and development of official chains of calibration,- State administration in metrological control for the State and

the European Community,- official qualification of laboratories for metrological verification,- metrological control registry,- research and development projects in metrological matters,- training of specialists in metrology.

The CEM is the custodian for national measurement standardsfor the base units of mass, length, electric current intensity, andthermodynamic temperature, and for the derived units forpressure, force, volume, plane angle and density of solids.

Spain has begun a limited network of Associated Laboratories;those that fulfil technical requirements as established for eachcase, are officially declared custodians of a given measurementstandard and recognised as Laboratories Associated to the CentroEspañol de Metrología.

Through agreements with the National Accreditation Organisation(Entidad Nacional de Acreditación, ENAC) it ensures traceability

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for the calibration laboratories accredited or with accreditationunder way, and it co-ordinates the national comparisons judgednecessary to confirm the technical competence of the accreditedcalibration laboratories.

There has been a reordering of the legal metrology responsibilities.CEM keeps the exclusive legislation capacity, the MetrologicalControl Registry, and representation of the country in Communityand international matters while metrological control is carried outby the several regional autonomous communities “ComunidadesAutónomas”.

Some of these Comunidades lack the required laboratories tocarry out the tests so that CEM acts as the supporting technicallaboratory for the regional services.

CEM carries out some activities that can be considered as purelycommercial:

- verification of ethylometers, dynamometer, opacity meters,- testing of medical measuring instruments,- general calibration of measuring instruments,- Certificates of conformity to standards or tests, and OIML

Certificates,- contracts for measurement assurance.

In particular in legal metrology, CEM does the tests for gas metersand the State metrological control of measuring instruments or

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systems for fluids other than water, as well as characterisationand certification of electromagnetic compatibility, EMC.

United States of America:

In the United States most of the authority over legal metrology isgiven to the State Weights and Measures Laboratories.

Also, diverse agencies exert authority over specific classes ofproducts. As an example, medicines are seldom tested, as thereare other government agencies that see to medicine safetyincluding accuracy of content and doses. Measuring instrumentsused by service companies – electric counters, water meters,gas meters - are regulated by other state agencies.

To promote uniform laws, regulations and standards (tests andtolerances for measuring instruments and the procedures forinspection of pre-packages), the National Institute for Scienceand Technology, NIST, sponsors the National Conference onWeights and Measures, NCWM.

The 50 States have adopted NIST Handbook 44 “Specifications,tolerances and other technical requirements for weighing andmeasuring devices” as recommended by the NCWM, as the legalcode governing weighing and measuring devices.

There are diverse laws and regulations throughout the nation.However, NIST Handbook 130 “Uniform laws and regulations”

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provides a general guide to the types of laws and regulations tobe enforced.

The need for uniformity in weights and measures was recognisedduring the second meeting of the NCWM, in 1906. The followingyear, basic outlines of a model law were developed and the first“Model Law” as such, was formally adopted by the Conference in1911.

With a single exception, the Uniform Weights and Measures Lawis automatically updated and adopted annually by all States thusbecoming, in fact, a national law. This is not the case for otherrelated laws that are not strictly the same among the States.

The goal of the NCWM regarding these laws and regulations is toachieve their acceptance in all States and local jurisdictions thathave authority over such matters. The purpose of the uniformlaws and regulations is to achieve, to the maximum extentpossible, standardisation in weights and measures laws andregulations among the various States and jurisdictions in order tofacilitate trade between the States, permit fair competition amongbusinesses, and provide uniform and sufficient protection to allconsumers in commercial weights and measures practices.

To ensure accurate, traceable measurements, and observanceof national and international standards, NIST manages the StateLaboratory Program.

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5.2. Assignments

Total harmony and co-ordination are essential between theNational Metrology Institute (NMI) and the legal metrology bodywhen they do not belong to the same organisation. As legalmetrology tasks expand, they require new technical capabilitieswhich may not yet exist but for which the National MetrologyInstitute can be prepared. Examples are the capacity of measuringmicrowaves to evaluate interference and compatibility inmeasuring instruments, and the new applications of highfrequencies. The legal metrology body can, in turn, help the NMIto identify and solve legal problems related to the promotion ofuniform measurements throughout the country.

Inspection and verification are not easy to concentrate at a nationallevel but private enterprises, when they take care of these tasks,must be supervised by an independent entity.

Legal metrology is global and normally cannot be assigned to asingle Ministry. This can be the case for health or the environmentwhen they have their own Ministry.

Standardisation can also be separated from legal metrology andwhen this is the case strong harmonisation between both shouldbe the goal.

Let us look again at a few examples in diverse countries:

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Brazil:

Changes are expected during the next years, particularly throughrevision of the law creating the Metrology System, implementationof metrological control, and a new relationship with the delegatedbodies.

Presently, metrological control carried out by INMETRO is doneby means of:

- regulations,- standards of procedures,- model technical evaluation and approval.

Delegated bodies are in charge of:

- verifications, both primary and subsequent,- control of pre-packages,- surveillance.

Canada:

Measurement Canada has the responsibility for:

- ensuring fairness in trade of goods and services,- defining measurement units,- calibrating and certifying measurement standards,- examining and approving measuring instruments,

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- verifying the accuracy and correct use of measuringinstruments used in trade,

- verifying net quantity products,- handling customer complaints.

Accredited bodies have to undergo surveillance audits fromMeasurement Canada.

France:

Co-ordination in metrology was assigned in 1969 to the BureauNational de Métrologie (BNM) who also had to fund the primarymetrology laboratories and to organise the chains of measurementstandards in the country. This last is, since 1994, the responsibilityof COFRAC (Comité Français d’Accréditation), while BNMcontinues to have scientific responsibility in accreditationcommissions.

First level tasks (measuring instruments) are more and moredelegated to private enterprises, supervised however, by the State(ISO 9001 quality assurance, COFRAC accreditation). It isestimated that there are around 3000 such bodies (77). Every twoyears they undergo a thorough inspection in addition to anunexpected one during the same period. The private bodies coverthe expenses of this supervision.

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Germany:

Supervisory verification authorities have been assigned to:

- verification, metrological evaluation and special tests onmeasuring instruments,

- accreditation and supervision of accredited testing centres formeasuring instruments for electricity, gas, water, and heat, aswell as the examination of technical competence of the staffof such centres,

- supervision of pre-packaged goods and of licensedcommercial containers,

- appointment and technical competence examination for thosein charge of public weighing machines,

- recognition of measuring instruments repairing andmaintenance services,

- supervision of manufacturers who carry out conformityassessment testing,

- inspection of the owners of measuring instruments.

The system of testing centres has been extended from electriccounters to measuring instruments for gas, water, and heat.Accreditation of a centre requires that it have facilities andequipment approved by the PTB. Germany considers that (48),given the legal requirements in force, there is no need for anadditional confirmation on the capacities of the verificationauthorities.

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Calibrations are assigned to competent laboratories, alsoaccredited by the PTB but who carry out their tasks under theirown responsibility.

Spain:

We have already mentioned the main responsibilities of CEM.

In addition, CEM represents Spain in several regional andinternational organisations: the Convention of the Metre, the OIML,EUROMET, WELMEC, and the European Commission, IMEKO.In the framework of the Convention of the Metre it has signed aMutual Recognition Agreement, whereby under set conditions,national measurement standards and calibration certificates arerecognised by the member countries.

It prepares training activities to bring metrology to enterprisesand other economic agents who nowadays, due to implementationof the ISO 9000 standards, require basic knowledge ofmetrological matters.

Accreditation of test centres corresponds to a national body, theEntidad Nacional de Acreditación (ENAC).

Although metrological control is done by the ComunidadesAutónomas, the municipalities carry out certain controls accordingto municipal ordinances, such as for example everything pertainingto road traffic that is handled by the Police.

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5.3. Administrative procedures

Some countries, Brazil and Mexico to mention just two of them,have procedure manuals with details, among others, such as:

- regulations,- staff assignments,- supervision,- fees for metrological services (tariffs),- documentation (formats),- gauging for each type of measurement,- measurement units,- quantity labelling in packages,- who is responsible for quality defects,- what constitutes a quality defect,- what is the cost of a quality defect,- pre-packaged goods,- surveillance of pre-packages,- infractions and penalties,- etc.

As an example of the degree of detail of such procedure manual,we will look at a few sections of a manual in use in Brazil (55):

“Merchandises the main use of which is based on linear extensionmust be traded in legal (SI) units of length; those based on surface,in area units; those that are solid or granulated at 20 ° C in massunits; those that are liquid or paste at 20 ° C in volume units;those traded in units, in effective number of units.

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“It is mandatory for packages or containers to have an indicationof the net content.

“All those who participate in the chain until merchandise reachesthe consumer are responsible for defects of quantity. There is adefect of quantity when the net content or the number is lowerthan that which is stated. Net content refers to the main producton sale.

“No merchandise (including special offers) other than that for whichthe package is destined may be included.

“All glass containers manufactured for sale of beverages musthave an indication of their capacity, stated in litres”.

5.4. Fees, fines, financial aspects

The legal metrology organisation will find it difficult to be self-supporting, as it has to carry out many tasks of supervision andconsultancy for which it cannot charge. In addition, very often thefees go to the national budget and are not directly assigned tothe legal metrology organisation. Even in highly industrialisedcountries, verification authorities can generate only around 80%of their operation costs.

Fees are usually charged for model approval, verification bothprimary and subsequent, accreditation of test centres andmaintenance services, and supervision.

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Fines are collected for infractions, which can be:- use of non authorised measure units,- use of instruments whose verification is no longer valid,- breaking, violating or making unusable markings or control

seals,- sale of pre-packaged products with a net content lower than

legal tolerances or than what is written on the label,- use of packages for pre-packaged products that do not show

the net amount or do so using units not legally authorised,- use of devices or instruments that exceed maximum tolerable

errors, detrimental to the consumer,- non compliance with resolutions on the installation of

measuring devices or counters,- disablement of measuring devices or counters.

The law establishes the penalty for each type of infraction.

As there are insufficient resources to inspect instruments andbusinesses with the ideal frequency, state inspectors and officialskeep records of the correctness of individual instruments and ofthe history of compliance of the business. Businesses with a badhistory in keeping their instruments working correctly or incomplying with the requirements for net contents in their packageswill be inspected more frequently. Constant violation of regulationscan bring about very high fines.

Those businesses and instruments with a bad history can beinspected up to twice a year. In Germany, for instance, someStates follow a policy whereby if an instrument is rejected as

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inaccurate, the inspector must perform another inspection at aspecified later date.

Any activity contrary to regulations is an administrative offence.For example, to pretend that an instrument has been verified orcertified when this is not true, is considered an administrativeoffence. This is one reason why terminology must be used carefullyfor metrological tests.

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6. Technical aspects

Technical aspects include everything related to thesetting up and operation of the physical facilities for legalmetrology tasks.

There must also be procedure manuals with details of theprotocols, standards and recommendations to be used,and the scientific and technical training of the staff to en-sure quality and credibility of all that pertains to legal me-trology.

There are many documents that give recommendationsand technical criteria for all technical aspects of legal me-trology.

Many technical issues must be taken into account when designingand implementing a national metrology system.

Scientific and technical issues concern the characteristics of thelaboratories to keep the conditions required by the measurementstandards, the unit realisation techniques and the verificationtechniques, and they include among others: building location,stability of terrain, type of construction, estimates for the spacesrequired by each activity, air conditioning, electrical supply,equipment, installation, testing activities, accessories (79).

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Some documents can be used as guides for the selection ofequipment for the most usual verification tests (69) related forinstance with mass, volume, length, angles, temperature, electricmeasurements, pressure measurements, physicochemicalmeasurements. Progress in instrumentation requires constantupdating in the selection of equipment but it is important to followas much as possible the international recommendations or thosefrom national metrology institutes of recognised scientific andtechnical competence.

The ways to carry out tasks must also be set down, usually inprocedure manuals, including protocols and standards forinstrument verification and technical application of regulations,sample selection for statistical sampling verification, protocols forintercomparisons, etc.

The International Organisation for Legal Metrology, OIML, hasseveral International Recommendations. A complete list can beseen on its Internet web page and a few are listed in theBibliography. They include such things as:

- classification of measuring instruments based on theiraccuracy,

- physical characteristics and metrological requirements fordifferent classes of weights,

- procedures for verification of commercial weights,- metrological and technical requirements for liquid in glass

thermometers,

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- tests for model approval and primary verification of thermalenergy counters,

- reports on tests done on audiometers,- labelling requirements for pre-packaged products,- etc.

similar documents are also available from national metrologyinstitutes such as CENAM in Mexico, NIST in the United Statesof America, and INMETRO in Brazil.

In a joint effort, the International Bureau of Weights and Measures,BIPM, the International Electrotechnical Commission, IEC, theInternational Federation of Clinical Chemistry, IFCC, theInternational Organisation for Standardisation, ISO, theInternational Organisation of Legal Metrology, OIML, theInternational Union of Pure and Applied Chemistry, IUPAC, andthe International Union of Pure and Applied physics, IUPAP,prepared a guide that sets the general rules for evaluation andexpression of uncertainty in measurement, applicable to manydifferent fields.

Technical tasks require staff with the appropriate education andtraining and in this there must be no improvisation.

This is why efforts are done all over the world to set uprecommendations for metrology engineers, technicians in legalmetrology, contents of programs of study, as well as a widediffusion of the study and training possibilities and the availablebibliography.

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Whatever its organisation, the national legal metrology systemmust be able to guarantee the quality and credibility of itsmeasurements. Quality of measurements as we have alreadymentioned requires the proper equipment, under properconditions, used by competent staff. To obtain internationalrecognition, it must also be able to guarantee traceability of itsmeasurement standards.

Credibility of the system will follow from its impartiality, from itsnot making any difference between traders, producers, consumersor government offices.

Laboratory accreditation, among others, seeks to ensure that testsand measurements done at these laboratories, in the scope oftheir accreditation, are accurate and reliable in the ranges requiredby the user.

Trust cannot be legislated; all those involved in the proceduresof legal metrology must act in such a way that the system willbe trusted.

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7. Regional and international legal metrology

The International Organisation of Legal Metrology, OIML,sets the general principles and the international harmoni-zation of legal metrology. Its work is disseminated mainlythrough its International Documents, its Recommendationsof normative status, and its Certificate System.

Other groups such as the European Co-operation in LegalMetrology, WELMEC, and the Inter American MetrologySystem, SIM, with its Working Group on Legal Metrology,are also working towards regional harmonisation and co-ordination of legal metrology.

Relevant today in Europe are what is known as “The NewApproach” on product regulation and “The Global Ap-proach” to conformity assessment.

7.1. The International Organisation of Legal Metrology, OIML.

The main international organisation for legal metrology is theInternational Organisation of Legal Metrology, OIML, based inParis, France.

One of the tasks of OIML is to establish general guiding principlesfor legal metrology. OIML advises governments on the mostconvenient ways of developing sound metrology policies,

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integrated into infrastructures with a wide scope. Its role is not tointerfere with government prerogatives but rather to see thatnational and regional policies conform to international harmonisedguides.

Harmonisation has two objectives:

- to eliminate technical barriers to trade of measuringinstruments,

- to facilitate commerce of products and services with acommercial value based on measurements.

OIML International Documents are prepared with the purpose ofguiding activities of the national metrology services. OIMLInternational Recommendations are considered as internationalstandards and focus on the metrological performance and thetesting procedures, not the design or manufacture of measuringinstruments.

Because of the wide variety of measuring instruments, OIML hasinstrument oriented Recommendations that specify performancerequirements and testing procedures for specific instruments, andresults oriented Recommendations having to do with theevaluation of the results of measurements.

Countries member of OIML are morally bound to transferinternational recommendations into their national regulations,insofar as the contents of the Recommendations refers to theirlegally regulated metrological sphere.

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OIML International Recommendations are the basis for EuropeanUnion Directives and thus, for the Member States, this moralobligation becomes a legal obligation.

OIML has established a system of Certificates, of voluntaryapplication, referring to the types or models of instruments, not tothe individual instruments manufactured according to said models.

National legal metrology services of more and more countriesaccept to accelerate the granting of national or regional modelapprovals on the basis of OIML certificates and associated testreports.

For developing countries, the OIML Certificate System is vital.Those countries that do not have facilities to carry out modelevaluation can replace these evaluations with the acceptance ofthe OIML certificates and they only have to solve the problem ofprimary verification of individual instruments.

Concerning developing countries, the Development Council ofthe OIML has set up a specific activity that includes identificationof technical and financial assistance and experts necessary forthe development of legal metrology.

The specific Secretariat (SP25 Developing Countries) has fiveunder-secretariats:

- principles, legal and administrative matters of legal metrology,- structure and operation of a national legal metrology service,

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- necessary equipment for the operation of a national legalmetrology service,

- recommendations from the point of view of developingcountries,

- teaching of legal metrology.

An OIML directory (42,43), updated online, provides the followinginformation for each of its 58 members and 51 correspondingmembers:

1. laws of metrology2. legal units of measurement3. instruments subject to legal control4. metrological control of quantities5. services responsible for metrology

5.1. national service of legal metrology5.2. local verification services5.3. laboratories responsible for maintaining national

measurement standards5.4. instrument calibration and evaluation systems

6. accreditation and certification systems6.1. accreditation systems for legal metrology,

calibration and testing laboratories – traceabilityto national, regional, international or foreignmeasurement standards

6.2. legal and applied metrological activities inproduct certification

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6.3. legal and applied metrological activities in ISO9000 quality management systems.

***

At a regional level there are co-ordination efforts by large blocks:Europe, Central and Eastern Europe, Asian Pacific,Commonwealth, Western Hemisphere. We will briefly mentiontwo of them: the European and the American.

7.2. Europe

7.2.1. Regional organisations in Europe

Members of WELMEC, (Western European Legal MetrologyCooperation) presently called the European Co-operation in LegalMetrology, consider their most important task to harmonise andco-ordinate the national and regional activities concerning all thetechnical problems of legal metrology in order to facilitate freetrading within Europe.

The principal aim of WELMEC is to establish a harmonised andconsistent approach to European legal metrology in the light of anumber of important developments:

- accumulated experience of the operation of the non-automaticweighing instruments Directive,

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- prolonged discussion of proposals for a measuring instrumentsDirective,

- the progress of a number of applicant countries towardsEuropean Union membership,

- increasing international trade in measuring instruments andmeasured goods,

- the different coverage of legal metrology in various countries.

7.2.2. The New Approach and the Global Approach in Europe

The European Single Market is an economic space where goods,services, capital and labour can circulate freely (23). The EuropeanUnion has developed original and innovative instruments toremove the barriers to free trade and this is one of the cornerstonesof the Single Market. Two of these instruments stand out:

- the so-called New Approach to product regulation,- the Global Approach to conformity assessment.

The working mechanism of the New Approach is based on:

- prevention of new barriers to trade, for instance by avoidingadoption of diverging national technical standards andregulations,

- mutual recognition, based on the following key elements:• products legally manufactured or marketed in one member

state should in principle move freely throughout the

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Community if they meet equivalent levels of protection,• in the absence of Community measures, Member States

are free to legislate on their territory,• barriers to trade which result from differences between

national legislations, may only be accepted, if nationalmeasures:< are necessary to satisfy mandatory requirements,< serve a legitimate purpose,< can be justified with regard to the legitimate purpose and

are proportional with the aims,- technical harmonisation is based on the following principles:

• legislative harmonisation is limited to essential requirements,• technical specifications of products are laid down in

harmonised standards,• application of harmonised European standards remains

voluntary and the manufacturer may always apply othertechnical specifications to meet the requirements,

• products manufactured in compliance with harmonisedstandards benefit from a presumption of conformity with thecorresponding essential requirements.

The Global Approach to conformity assessment is based on thefollowing guiding principles applicable in the regulated and in thenon regulated fields:

- the use of modules for the various phases of conformityassessment procedures and laying down of criteria for theuse of these procedures,

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- generalised use of European standards relating to qualityassurance (EN ISO 9000 series) and of the requirements tobe fulfilled by conformity assessment bodies,

- promotion of setting up of accreditation systems and the useof intercomparison techniques among Member States,

- promotion of mutual recognition agreements concerningtesting and certification in the non-regulatory sphere,

- minimisation of differences in the existing qualityinfrastructures,

- promotion of international trade through mutual recognitionagreements, co-operation and technical assistanceprogrammes.

Conformity assessment is based on:

- manufacturers’ internal design and production control activities,- third party type examination combined with manufacturers’

internal production control activities,- third party type or design examination combined with third

party approval of product or production quality assurancesystems, or third party product verification,

- third party unit verification of design and production,- third party approval of full quality assurance systems.

Before placing a product on the Community market, themanufacturer must subject the product to a conformity assessmentprocedure provided for in the applicable directive, with the viewto affixing the CE marking.

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Member States must presume that products bearing the CEmarking comply with all provisions of the applicable directivesproviding for its affixing. Accordingly, Member States may notprohibit, restrict or impede the placing on the market and puttinginto service in their territory of products bearing the CE markingunless the provisions relating to CE marking are incorrectlyapplied.

New Approach directives are of total harmonisation and MemberStates must revoke any contradictory national legislation. Thedirectives are binding in regard to the results to be obtained butthey leave the Member States at liberty to select ways and means.

In brief, we can say that in the European Single Market,responsibility is transferred step by step to the manufacturer ofmeasuring instruments, as long as he has in place a quality systemrecognised and supervised at regular intervals by a certificationbody (notified body) designated by the member state.

In the case of measuring instruments, with the New Approachonly the essential requirements to ensure measuring certainty ofthe measuring instruments will be laid down in the European UnionDirectives and they will be based on OIML activities. Technicalrequirements to be met by measuring instruments will be laid downin the respective European standards (CEN and CENELEC).

However, there cannot be free circulation of goods and aliberalised access to markets without the proper control of

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measurements and this entails an obligation for marketsurveillance on the part of the Member States as laid down in theEC directives.

7.3. America

In the Western Hemisphere the Inter American System ofMetrology, SIM, has been created to promote metrology inAmerica.

SIM groups the countries of the Western Hemisphere in five largeregions: NORAMET for the countries of North America, CAMETfor those of Central America, ANDIMET the Andean countries,SURAMET the countries of South America, and CARIMET theCaribbean countries.

SIM has established a Legal Metrology Working Group with twosubgroups. Both have as their objective the harmonisation of legalmetrology requirements and activities in the Americas inconsideration of OIML Recommendations and Documents.

Subgroup 1 addresses Laws and Regulations and its scope is tocontribute to developing and maintaining mutual confidencebetween Legal Metrology Services in the Americas through:

- harmonising elements of legal metrology regulations,- promoting the consistent interpretation and application of

legal metrology regulations.

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The scope of Subgroup 2, Metrological Control of MeasuringInstruments and Pre-packaged Products is to contribute tominimise technical barriers to trade through:

- providing confidence in measuring instruments under legalmetrological control used for carrying out measurements forequity in trade, public and worker health and safety, andenvironmental protection,

- developing a regional mutual acceptance arrangement foraccepting and utilising type evaluation,

- providing harmonised means and procedures for verificationand tests.

For instance, a recent survey among SIM members showed thereis still no uniform application of requirements for metrologicalcontrol of pre-packaged products and that, particularly, not all legalmetrology services are using the corresponding OIMLRecommendation. Currently, SIM members are actively workingto modify this situation and to attain a better regionalharmonisation.

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8. The future of legal metrology

It is necessary to be prepared for the newchallenges faced by legal metrology, thatwill come from the deep changes broughtabout by new technologies and technicalprogress.

In September 2002 an international seminar sponsored by theOIML was held in Saint-Jean-de-Luz (France) under the title Whatwill legal metrology be in the year 2020. This seminar reviewedthe evolutions that legal metrology is facing, and the long-termperspectives in the context of which the goals of legal metrologywill have to be attained.

Some of the relevant points reported in its Conclusions and Report(63) are:

“In the not too distant future, it is likely that all technical progressand all new technologies in measuring instruments will emanatefrom a limited number of multinational manufacturers and usedworldwide, and very often at a lower cost than traditionaltechnologies. National manufacturers will probably limit theiractivity to adapting these international products to specific localneeds.

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“Metrology is often considered as a necessity for industry thatshould be financed by the private sector, and legal metrology istoo often considered as an old fashioned regulatory task that couldbe replaced by standardisation and the promotion of quality, bothvoluntary… However, some international organisations(essentially the WTO and UNIDO) have understood that anadequate metrological infrastructure is necessary fordevelopment.

“’Stand-alone’ instruments will give way to systems that areintegrated in networks, perform complex functions, associatedifferent kinds of measurements and manage numerousmeasurement results. The elements of these systems will not becomplete instruments but sensors, modules of instruments anddata processing systems, all of which will interact with each other.

“Instruments and systems will be able to carry out tasks that arepresently reserved only for metrology or other specialized bodies;self-verification, maintenance assistance and adaptation of theirbehaviour to environmental conditions or to measuring conditions.Future instruments and systems may even be able to developrelatively intelligent fraudulent behaviour and to prevent suchbehaviour from being detected by legal metrology officials.

“The scope of these measuring systems will be considerablyenlarged. They will cover a wide variety of measurements andquantities in nearly all fields of human activity. The integration ofmeasuring devices in global networks, often using the Internet,

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will require legal metrology to address the entirety of thesenetworks.

“At national level, legal metrology authorities will have to face upto the new, considerably higher stakes of metrology. They willhave to carry out their tasks with limited or partial resources, andstill address a wider scope of measurements and advancedtechnologies. They will need new skills to deal with these newfields and technologies, probably with fewer staff. They will haveto demonstrate the utility of legal metrology to political decision-makers whose awareness of technical issues will be very low.

“International harmonisation, mutual confidence and mutualrecognition among legal metrology bodies and authorities are notonly a necessity for trade facilitation, but also for fulfilling themissions of legal metrology at national level. Legal metrology workwill have to be globalised, or it will be ineffective.

“The OIML must also urgently begin to study the general structureof conformity assessment procedures in order to adapt them tonew technologies, to the new structure of measuring systemsand to that of production and maintenance. An OIML Documentshould be produced to give guidance on the new skills requiredby enforcement authorities and conformity assessment bodies.Such skills are required for legal metrology authorities,enforcement officers and conformity assessment officers, due tothe evolution in technologies.”

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