Beamex White Paper - How Often Should Instruments Be Calibrated

8/13/2019 Beamex White Paper - How Often Should Instruments Be Calibrated

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How often shouldinstruments be

calibrated

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Beamex

Calibration White Paper


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BEAMEX Calibration White Paper

How often should instruments be calibrated 2www.beamex.com

Plants can improve their efficiency and reduce costsby performing calibration history trend analysis. Bydoing it, a plant is able to define which instrumentscan be calibrated less frequently and which should becalibrated more frequently. Calibration history trendanalysis is only possible with calibration softwarethat provides this functionality.

Adjusting calibration intervals based on historytrend analysis Manufacturing plants need to be absolutely confident thattheir instrumentation products temperature sensors,pressure transducers, flow meters and the like are performingand measuring to specified tolerances. If sensors drift out oftheir specification range, the consequences can be disastrousfor a plant, resulting in costly production downtime, safetyissues or possibly leading to batches of inferior quality goodsbeing produced, which then have to be scrapped.

Most process manufacturing plants will have some sortof maintenance plan or schedule in place, which ensuresthat all instruments used across the site are calibrated at theappropriate times. However, with increasing demands andcost issues being placed on manufacturers these days, the timeand resources required to carry out these calibration checksare often scarce. This can sometimes lead to instrumentsbeing prioritised for calibration, with those deemed criticalenough receiving the required regular checks, but for othersensors that are deemed less critical to production, beingcalibrated less frequently or not at all.

But plants can improve their efficiencies and reduce costsby using calibration history trend analysis, a function

available within Beamex CMX calibration software. Withthis function, the plant can analyze whether it shouldincrease or decrease the calibration frequency for all itsinstruments.

Cost savings can be achieved in several ways. First, bycalibrating less frequently where instruments appear to behighly stable according to their calibration history. Second,by calibrating instruments more often when they are locatedin critical areas of the plant, ensuring that instruments arechecked and corrected before they drift out of tolerance.This type of practise is common in companies that employan effective Preventive Maintenance regime. The analysesof historical trends and how a pressure sensor, for example,drifts in and out of tolerance over a given time period, is

only possible with calibration software that provides thistype of functionality.

Current practices in process plants

But in reality, how often do process plants actually calibratetheir instruments and how does a maintenance manager orengineer know how often to calibrate a particular sensor?

In March 2010, Beamex conducted a survey that askedprocess manufacturing companies how many instrumentsin their plant required calibrating and the frequency withwhich these instruments had to be calibrated. The surveycovered all industry sectors, including pharmaceuticals,chemicals, power and energy, manufacturing, service, foodand beverage, oil and gas, paper and pulp.

Interestingly, the survey showed that from all industrysectors, 56% of the respondents said they calibrated theirinstruments no more than once a year.

However, in the pharmaceuticals sector, 59% said theycalibrated once a year and 30% said they calibrated twice

a year.Perhaps unsurprisingly, due to it being a highly regulatedindustry, the study proved also that the pharmaceuticalssector typically possesses a significantly higher number ofinstruments per plant that require calibrating. In addition,

How often shouldinstruments be calibrated

Plants can improve their efficiencies

and reduce costs by using calibration

history trend analysis,

a function available within Beamex

CMX calibration software.

Sensors that are found to be

highly stable do not need to be

re-calibrated as often as sensors that

tend to drift.


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these plants also calibrate their instruments more frequentlythan other industry sectors.

The benefits of analyzing calibration historytrends

But regardless of the industry sector, by analysing aninstruments drift over time (ie. the historical trend)companies can reduce costs and improve their efficiencies.

Pertti Mki is Area Sales Manager at Beamex. He specialisesin selling the Beamex CMX to different customers across allindustry sectors. He comments: The largest savings fromusing the History Trend Option are in the pharmaceuticalssector, without doubt, but all industry sectors can benefitfrom using the software tool, which helps companiesidentify the optimal calibration intervals for instruments.

The trick, says Mki, is determining which sensors shouldbe re-calibrated after a few days, weeks, or even years ofoperation and which can be left for longer periods, withoutof course sacrificing the quality of the product or process orthe safety of the plant and its employees. Doing this, he says,enables maintenance staff to concentrate their efforts onlywhere they are needed, therefore eliminating unnecessarycalibration effort and time.

But there are other, perhaps less obvious benefits of lookingat the historical drift over time of a particular sensor or set ofmeasuring instruments. As Mki explains: When an engineerbuys a particular sensor, the supplier provides a technicalspecification that includes details on what the maximumdrift of that sensor should be over a given time period. WithCMXs History Trend Option, the engineer can now verifythat the sensor he or she has purchased, actually performed

within the specified tolerance over a certain time period. If ithasnt, the engineer now has data to present to the supplier tosupport his findings.

But thats not all. The History Trend function also meansthat a plant can now compare the quality or performanceof different sensors from multiple manufacturers in a given

location or set of process conditions. This makes it aninvaluable tool for maintenance or quality personnel who,in setting up a new process line for example, can use thefunctionality to compare different sensor types to see whichone best suits the new process.

Calibration software such as CMX can also help with theplanning of calibration operations. Calibration schedulestake into account the accuracy required for a particularsensor and the length of time during which it has previously

been able to maintain that degree of accuracy. Sensors thatare found to be highly stable do not need to be re-calibratedas often as sensors that tend to drift.

The History Trend function enables users to plan theoptimal calibration intervals for their instruments. Onceimplemented, maintenance personnel, for example, cananalyze an instruments drift over a certain time period.History Trend displays the instruments drift over a givenperiod both numerically and graphically. Based on thisinformation, it is then possible to make decisions andconclusions regarding the optimal calibration interval andthe quality of the instruments with respect to measurementperformance.

The History Trend window enables users to view keyfigures of several calibration events simultaneously, allowing

to evaluate the calibrations of a position or a device for a longertime period compared to the normal calibration result view.For example, the user can get an overview of how a

particular device drifts between calibrations and alsowhether the drift increases with time. Also, the engineercan analyze how different devices are suited for use in aparticular area of the plant or process.

Reporting is straightforward and the user can even tailorthe reports to suit his or her individual needs, using theReport Design tool option.

The function enables users to plan

the optimal calibration intervals for

their instruments.

History Trend displays the instruments

drift over a given period both

numerically and graphically.


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Calibration history trend analysis allows you toanalyze the instruments drift over a certain timeperiod.

The Beamex CMX stores every calibration eventinto the database; the history trend is madeautomatically without any extra manual work.

The Beamex

CMX also indicates when newdevices have been installed and calibrated. Thishelps in comparing differences between devices.

The graphical display of the history trend helps invisualizing and optimizing the calibration intervalfor the instruments.

CALIBRATION HISTORY TREND ANALYSIS

H I S T O R Y T R E N D U S E R

- I N T E R F A C E

H I S T O R Y T R E N D R E P O R T

SUMMARY

The benefits of calibration historytrend analysis:

Analyzing and determining the optimal calibrationinterval for instruments

Conclusions can be made regarding the quality of

a particular measuring instrument Time savings: faster analyses is possible when

compared to traditional, manual methods Enables engineers to check that the instruments

they have purchased for the plant are performingto their technical specifications and are not driftingout of tolerance regularly

Supplier evaluation: the performance and quality ofdifferent sensors from different manufacturers canbe compared quickly and easily.

When calibration frequency can be decreased: If the instrument has performed to specification

and the drift has been insignificant compared to itsspecified tolerance

If the instrument is deemed to be non-critical or ina low priority location

When calibration frequency should be increased: If the sensor has drifted outside of its specified

tolerances during a given time period If the sensor is located in a critical process or area

of the plant and has drifted significantly compared

to its specified tolerance over a given time period When measuring a sensor that is located in an area

of the plant that has high economic importance forthe plant

Where costly production downtime may occur as aresult of a faulty sensor

Where a false measurement from a sensor couldlead to inferior quality batches or a safety issue


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ISO 9001:2008 quality management requirements

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All specications are subject to change without prior notice. Beamex Oy Ab 2013. All rights reserved.Beamex is a trademark of Beamex Oy Ab.

Beamex White Paper - How Often Should Instruments Be Calibrated

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