Day 2 - Metrology

Metrology

The science of measurement and its application

Measurement

The process of obtaining information about a quantity through measurement

Scientific metrology

The area of metrology concerned with realization of units measurement standards and fundamental research

Industrial metrology

The area of metrology applied to manufacturing production calibration quality control inspection and process control

Legal metrology

The area of metrology concerned with regulated measurements and legal requirements related to trade health and safety

Measurement system

A set of one or more measuring instruments and other devices assembled and adapted to generate measured quantity values

Measuring instrument

A device used to perform measurements and provide an indication or measurement result

Measurand

The quantity intended to be measured

Specified measurement conditions

The conditions under which a measurement is performed such as temperature stability immersion depth and ambient conditions

RTD temperature sensor

An instrument used to measure temperature

Pressure gauge

An instrument used to measure pressure

Temperature measurand

The temperature of the specified medium at the specified conditions

Pressure measurand

The pressure of the specified medium at the specified conditions

Connection wiring

A device or component that connects the RTD sensor to the indicator or measuring instrument

Indicator

An instrument that measures or displays the value associated with the input from a sensor

Measurement result

The value obtained from a measurement together with relevant information about the measurement

Temperature measurement system

A measurement system consisting of an RTD sensor connection wiring and indicator used to generate a temperature measurement result

Scientific metrology example

Maintaining national measurement standards such as a reference thermometer or realization of units

Industrial metrology example

Calibrating an industrial temperature indicator against a reference thermometer

Legal metrology example

Checking weighing instruments used for regulated commercial transactions such as retail scales or fuel dispensers

Metrology purpose

To provide the scientific and technical foundation for measurement

Measurement purpose

To define what is being measured and how it is measured

Measurement system purpose

To combine instruments devices and specified conditions to generate measurement results

Measurement result purpose

To provide a value associated with the quantity being measured and its uncertainty

Measurement uncertainty

Information that characterizes the dispersion of quantity values attributed to a measurand

Measurement traceability

A property that connects a measurement result to a reference through a documented chain of calibrations

Measurement validity

Confidence that measurement results remain reliable comparable and defensible

ISO/IEC 17025:2017

An international standard specifying requirements for the competence impartiality and consistent operation of testing and calibration laboratories

ISO/IEC 17025 Clause 6.4

Equipment

ISO/IEC 17025 Clause 6.5

Metrological traceability

ISO/IEC 17025 Clause 7.2

Selection verification and validation of methods

ISO/IEC 17025 Clause 7.6

Evaluation of measurement uncertainty

ISO/IEC 17025 Clause 7.7

Ensuring the validity of results

ISO/IEC 17025 Clause 7.8

Reporting of results

How does metrology support measurement?

It provides the scientific and technical foundation for measurement

How does a measurement system generate a result?

It combines measuring instruments and other devices under specified conditions to generate measured quantity values

Can a measurement system consist of only one measuring instrument?

Yes

What is the measurand in an RTD example?

The temperature of the specified medium at the specified conditions

What is the measurand in a pressure gauge example?

The pressure of the specified medium at the specified conditions

What does the measurement system include in the RTD example?

The RTD sensor connection wiring indicator and specified measurement conditions

What is the relationship between metrology and measurement?

Metrology provides the scientific and technical foundation for measurement

What is the relationship between measurement and measurement system?

Measurement defines what is measured and how while the measurement system combines the necessary instruments and conditions

What is the relationship between measurement system and measurement result?

The measurement system generates the measured quantity value that becomes the measurement result

What does uncertainty add to a measurement result?

It provides information about the variability or dispersion associated with the result

What does traceability add to a measurement result?

It provides a documented link to an appropriate reference

What does validity support?

It supports reliable comparable and defensible measurement results

Why is metrology important in calibration?

It provides the scientific foundation and terminology needed to understand and perform reliable measurements

Day 2 goal

Understand metrology its major areas measurement systems and the concept of the measurand then connect these fundamentals to ISO/IEC 17025:2017