number and reference together expressing magnitude of a quantity

EXAMPLE 1 Length of a given rod:

5.34 m or 534 cm

EXAMPLE 2 Mass of a given body:

0.152 kg or 152 g

EXAMPLE 3 Curvature of a given arc:

112 m^{−1}

EXAMPLE 4 Celsius temperature of a given sample:

−5 °C

EXAMPLE 5 Electric impedance of a given circuit element at a given frequency, where j is the imaginary unit:

(7 + 3j) Ω

EXAMPLE 6 Refractive index of a given sample of glass:

1.32

EXAMPLE 7 Rockwell C hardness of a given sample:

43.5 HRC

EXAMPLE 8 Mass fraction of cadmium in a given sample of copper:

3 µg/kg or 3 ·10^{−9}

EXAMPLE 9 Molality of Pb^{2+ }in a given sample of water:

1.76 µmol/kg

EXAMPLE 10 Arbitrary amount-of-substance concentration of lutropin in a given sample of human blood plasma (WHO International Standard 80/552 used as a calibrator):

5.0 IU/l, where “IU” stands for “WHO International Unit"

NOTE 1 According to the type of reference, a quantity value is either

- a product of a number and a measurement unit (see Examples 1, 2, 3, 4, 5, 8 and 9); the measurement unit one is generally not indicated for quantities of dimension one (see Examples 6 and 8), or

- a number and a reference to a measurement procedure (see Example 7), or

- a number and a reference material (see Example 10).

NOTE 2 The number can be complex (see Example 5).

NOTE 3 A quantity value can be presented in more than one way (see Examples 1, 2 and 8).

NOTE 4 In the case of vector or tensor quantities, each component has a quantity value.

EXAMPLE Force acting on a given particle, e.g. in Cartesian components (F_{x}; F_{y}; F_{z}) = (−31.5; 43.2; 17.0) N.

ANNOTATION (informative) [3 December 2013] The term "quantity value" was chosen as the first (preferred) term in order to take advantage of the adjectival use of a noun in the English language. However, it is recognized that the more commonly used expression is the second term, "value of a quantity", or even the third term, "value" (when there is no possible ambiguity or confusion; for example, it is not necessary to write "quantity value of a measurand").

- 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

- 2.1 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

- 3.1 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

- 4.1 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

- 5.1 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