Introduction METROLOGY

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METROLOGY FGB 20102 What is metrology? It is the science of weights and measures Refers primarily to the measurements of

length, weight, time, etc. It also includes other engineering measurements for the establishment of a flat, plane reference surface To ensuring these process meet specific degrees of both accuracy and precision

METROLOGY MET 3012 Accuracy is the degree of conformity of a measured or

calculated quantity to its actual, nominal, absolute, or some other reference, value Precision Is the degree of mutual agreement or repeatability among a series of individual measurements, values, or results.


METROLOGY MET 3012 What is a Measurement?

A measurement is an act of assigning a specific value to a physical variable The physical variable becomes the measured variable Measurements provide a basis for judgments about

Process information Quality assurance Process control

METROLOGY MET 3012 Measurable Parameters

What do we want to measure?- Length or distance - Temperature - Viscosity - Time - Forces - Strain - Resistance - Depth - etc. - Mass - Elemental composition - Displacements or distortions - Pressure - Stress - Friction - Roughness - Intensity


Measurement Systems and Tools Measurement systems are important tools for the quantification of the physical variable Measurement systems extend the abilities of the human senses, while they can detect and recognize different degrees of physical variables For scientific and engineering measurement, the selection of equipment, techniques and interpretation of the measured data are important

METROLOGY MET 3012 Importance of Metrology In human relationships, things must be

counted and measured Metrology is an absolute necessity for human development

This necessity increased greatly with the advent of the industrial age

As society develops further, metrology must

also be refined further


How Important are Measurements? Measurement is the language of science It helps us communicate about size, quantity, position, condition, time, etc. Simple measurement errors can cost a company a contract, work, jobs, and lots of money Three areas to which the basic principles of measurement can be applied

Communication of the measurement Act and application of the measurement Codification of the measurement


Human Interaction in Measurements Almost always require the use of vision

Other senses not always good at measurement They rely on the visual process At what size do things become to small to measure? Handling and/or perception problems Limits of vision/ perception without aid or assistance

Measurements usually require tools

What happens if object is too small to perceive?

METROLOGY MET 3012 What is Microsystems Metrology

Measurement of physical dimensions of Microsystems or structures that are at the dimension scale below our ability to perceive without the help of measurements systems or instruments Microsystems: IC, MEMS Microstructures: Line widths, film thickness, surface structure and roughness, step heights, particle size, atomic composition, defect inspections, etc Nanosystem metrology is emerging now!

METROLOGY MET 3012 Where Metrology at the

Micro Level is Used Precision engineering and measurements Micron and nano manufacturing Research and development Calibration of instruments and standards


International System of Units (abbreviated SI from the French phrase, Systme International d'Units) is the most widely used system of units. Ex. The unit of length (or distance or linear size) is the meter (m),

METROLOGY MET 3012 Imperial Units

The imperial units were mostly used in the United Kingdom and related countries The imperial units are now used mainly in the United States, where they are known as US customary units Ex. inch, foot, yard, mile

METROLOGY MET 3012 SI Base Units

Basic Unit of Length Meter is fundamental unit of length in the metric system. The meter was originally defined as 1/10,000,000 of the distance between the equator and either pole; however, the original survey was inaccurate and the meter was later defined simply as the distance between two scratches on a bar made of a platinum-iridium alloy and kept at Sevres, France, near Paris. More recently, it has been defined as the distance light travels through a vacuum in 1/299,792,458 of a second. The meter is now the legal standard of length for most of the world, other standards, such as the yard, being defined in terms of the meter.

METROLOGY MET 3012 SI Base Units Basic Unit of Mass Kilogram

is fundamental unit of mass is equal to the mass of the international prototype kilogram (a platinum-iridium cylinder) kept at the Bureau International des Poids et Mesures (BIPM), Svres, Paris (1st CGPM (1889), CR 34-38).

METROLOGY MET 3012 SI Base Units Basic Unit of Time Second is fundamental unit of time is the

duration of exactly 9 192 631 770 periods of the radiation corresponding to the transition between two hyperfine levels of the ground state of the caesium-133 atom at a temperature of 0 K (13th CGPM (1967-1968) Resolution 1, CR 103).

METROLOGY MET 3012 SI Base Units Basic Unit of Electrical Current Ampere is fundamental unit of electrical

current is the constant current which, if maintained in two straight parallel conductors, of infinite length and negligible cross-section, placed 1 meter apart in a vacuum, would produce a force between these conductors equal to 210 7 Newton per meter of length (9th CGPM (1948) Resolution 7, CR 70).

METROLOGY MET 3012 SI Base Units Basic Unit of thermodynamic Temperature Kelvin is fundamental unit of thermodynamic

temperature (or absolute temperature) is the fraction 1/273.16 (exactly) of the thermodynamic temperature at the triple point of water (13th CGPM (1967) Resolution 4, CR 104).

METROLOGY MET 3012 SI Base Units

Basic Unit of Amount of Substance Mole is fundamental unit of amount of substance is the amount of substance which contains as many elementary entities as there are atoms in 0.012 kilograms of pure carbon-12 (14th CGPM (1971) Resolution 3, CR 78). (Elementary entities may be atoms, molecules, ions, electrons, or particles.) It is approximately equal to 6.022141991023 units (Avogadro's number).

METROLOGY MET 3012 SI Base Units Basic Unit of Luminous Intensity Candela is fundamental unit of luminous

intensity is the luminous intensity, in a given direction, of a source that emits monochromatic radiation of frequency 5401012 hertz and that has a radiant intensity in that direction of 1/683 watt per steradian (16th CGPM (1979) Resolution 3, CR 100).

METROLOGY MET 3012 SI Dimensionless UnitsName radian Symbol rad Quantity Angle Definition The unit of angle is the angle subtended at the centre of a circle by an arc of the circumference equal in length to the radius of the circle. There are 2 radians in a circle. The unit of solid angle is the solid angle subtended at the centre of a sphere of radius r by a portion of the surface of the sphere having an area r2. There are 4 steradians on a sphere.



Solid angle

METROLOGY MET 3012SI Derived Units With Special NamesQuantity Frequency Force Energy Power Pressure, Stress Luminous flux I luminance Electric charge Electric potential difference Electric Resistance Electric Capacitance Magnetic flux Magnetic Flux density Inductance Electric Conductance Radioactivity Adsorbed Dose (of ionizing radiation) Equivalent Dose (of ionizing radiation) Catalytic activity Thermodynamic Temperature S-1 Kg m s-1 Nm J/s N/m2 cd sr lm/m2 As W/A V/A C/V Kg m2 s-2 A-1 Wb/m2 Wb/A -1 s-1 J/kg J/kg Mol/s K Name Hertz Newton Joule Watt Pascal Lumen Lux Coulomb Volt Ohm Farad Weber Tesla Henry Siemens Becquerel Gray Sievert Katal Degree of Celsius Symb ol Hz N J W Pa Lm Lx C V F Wb T H S Bq Gy Sv Kat0

Expressed in base units



Convert Measurement Units of Length Meter to Inches

multiply by 39.37 multiply by 3.281 multiply by 1.094 multiply by 6.214 E-4.

Meter to Feet

Meter to Yards

Meter to Miles

METROLOGY MET 3012 Convert Measurement Units of Mass Kilogram

to Pound

Multiply by 2.204621