Notes

NOTE 1 Examination of a nominal property provides a nominal property value and associated uncertainty. This uncertainty is not a measurement uncertainty.

NOTE 2 Reference materials with or without assigned quantity values can be used for measurement precision control whereas only reference materials with assigned quantity values can be used for calibration or measurement trueness control.

NOTE 3 'Reference material' comprises materials embodying quantities as well as nominal properties.

EXAMPLE 1 Examples of reference materials embodying quantities:

a) water of stated purity, the dynamic viscosity of which is used to calibrate viscometers;

b) human serum without an assigned quantity value for the amount-of-substance concentration of the inherent cholesterol, used only as a measurement precision control material;

c) fish tissue containing a stated mass fraction of a dioxin, used as a calibrator.

EXAMPLE 2 Examples of reference materials embodying nominal properties:

a) colour chart indicating one or more specified colours;

b) DNA compound containing a specified nucleotide sequence;

c) urine containing 19-androstenedione.

NOTE 4 A reference material is sometimes incorporated into a specially fabricated device.

EXAMPLE 1 Substance of known triple-point in a triple-point cell.

EXAMPLE 2 Glass of known optical density in a transmission filter holder.

EXAMPLE 3 Spheres of uniform size mounted on a microscope slide.

NOTE 5 Some reference materials have assigned quantity values that are metrologically traceable to a measurement unit outside a system of units. Such materials include vaccines to which International Units (IU) have been assigned by the World Health Organization.

NOTE 6 In a given measurement, a given reference material can only be used for either calibration or quality assurance.

NOTE 7 The specifications of a reference material should include its material traceability, indicating its origin and processing (Accred. Qual. Assur.:2006) ^[45].

NOTE 8 ISO/REMCO has an analogous definition ^[45] but uses the term “measurement process” to mean 'examination' (ISO 15189:2007, 3.4), which covers both measurement of a quantity and examination of a nominal property.

1 Quantities and units

• 1.1 quantity
• 1.2 kind of quantity
• 1.3 system of quantities
• 1.4 base quantity
• 1.5 derived quantity
• 1.6 International System of Quantities
• 1.7 quantity dimension
• 1.8 quantity of dimension one
• 1.9 measurement unit
• 1.10 base unit
• 1.11 derived unit
• 1.12 coherent derived unit
• 1.13 system of units
• 1.14 coherent system of units
• 1.15 off-system measurement unit
• 1.16 International System of Units
• 1.17 multiple of a unit
• 1.18 submultiple of a unit
• 1.19 quantity value
• 1.20 numerical quantity value
• 1.21 quantity calculus
• 1.22 quantity equation
• 1.23 unit equation
• 1.24 conversion factor between units
• 1.25 numerical value equation
• 1.26 ordinal quantity
• 1.27 quantity-value scale
• 1.28 ordinal quantity-value scale
• 1.29 conventional reference scale
• 1.30 nominal property

2 Measurement

• 2.1 measurement
• 2.2 metrology
• 2.3 measurand
• 2.4 measurement principle
• 2.5 measurement method
• 2.6 measurement procedure
• 2.7 reference measurement procedure
• 2.8 primary reference measurement procedure
• 2.9 measurement result
• 2.10 measured quantity value
• 2.11 true quantity value
• 2.12 conventional quantity value
• 2.13 measurement accuracy
• 2.14 measurement trueness
• 2.15 measurement precision
• 2.16 measurement error
• 2.17 systematic measurement error
• 2.18 measurement bias
• 2.19 random measurement error
• 2.20 repeatability condition of measurement
• 2.21 measurement repeatability
• 2.22 intermediate precision condition of measurement
• 2.23 intermediate measurement precision
• 2.24 reproducibility condition of measurement
• 2.25 measurement reproducibility
• 2.26 measurement uncertainty
• 2.27 definitional uncertainty
• 2.28 Type A evaluation of measurement uncertainty
• 2.29 Type B evaluation of measurement uncertainty
• 2.30 standard measurement uncertainty
• 2.31 combined standard measurement uncertainty
• 2.32 relative standard measurement uncertainty
• 2.33 uncertainty budget
• 2.34 target measurement uncertainty
• 2.35 expanded measurement uncertainty
• 2.36 coverage interval
• 2.37 coverage probability
• 2.38 coverage factor
• 2.39 calibration
• 2.40 calibration hierarchy
• 2.41 metrological traceability
• 2.42 metrological traceability chain
• 2.43 metrological traceability to a measurement unit
• 2.44 verification
• 2.45 validation
• 2.46 metrological comparability of measurement results
• 2.47 metrological compatibility of measurement results
• 2.48 measurement model
• 2.49 measurement function
• 2.50 input quantity in a measurement model
• 2.51 output quantity in a measurement model
• 2.52 influence quantity
• 2.53 correction

3 Devices for measurement

• 3.1 measuring instrument
• 3.2 measuring system
• 3.3 indicating measuring instrument
• 3.4 displaying measuring instrument
• 3.5 scale of a displaying measuring instrument
• 3.6 material measure
• 3.7 measuring transducer
• 3.8 sensor
• 3.9 detector
• 3.10 measuring chain
• 3.11 adjustment of a measuring system
• 3.12 zero adjustment of a measuring system

4 Properties of measuring devices

• 4.1 indication
• 4.2 blank indication
• 4.3 indication interval
• 4.4 nominal indication interval
• 4.5 range of a nominal indication interval
• 4.6 nominal quantity value
• 4.7 measuring interval
• 4.8 steady-state operating condition
• 4.9 rated operating condition
• 4.10 limiting operating condition
• 4.11 reference operating condition
• 4.12 sensitivity of a measuring system
• 4.13 selectivity of a measuring system
• 4.14 resolution
• 4.15 resolution of a displaying device
• 4.16 discrimination threshold
• 4.17 dead band
• 4.18 detection limit
• 4.19 stability of a measuring instrument
• 4.20 instrumental bias
• 4.21 instrumental drift
• 4.22 variation due to an influence quantity
• 4.23 step response time
• 4.24 instrumental measurement uncertainty
• 4.25 accuracy class
• 4.26 maximum permissible measurement error
• 4.27 datum measurement error
• 4.28 zero error
• 4.29 null measurement uncertainty
• 4.30 calibration diagram
• 4.31 calibration curve

5 Measurement standards (Etalons)

• 5.1 measurement standard
• 5.2 international measurement standard
• 5.3 national measurement standard
• 5.4 primary measurement standard
• 5.5 secondary measurement standard
• 5.6 reference measurement standard
• 5.7 working measurement standard
• 5.8 travelling measurement standard
• 5.9 transfer measurement device
• 5.10 intrinsic measurement standard
• 5.11 conservation of a measurement standard
• 5.12 calibrator
• 5.13 reference material
• 5.14 certified reference material
• 5.15 commutability of a reference material
• 5.16 reference data
• 5.17 standard reference data
• 5.18 reference quantity value