Measurand

The measurand, or measured quantity, is the physical quantity in metrology, subject to measurement. The term is used for a measured quantity in the general sense as well as a particular quantity.

A measurand in the general sense refers to a physical quantity that was or will be subject to measurement, e.g. mass, power or temperature.

A particular quantity is a (derived) quantity describing a specific physical characteristic, e.g. the volume of a body or the resistance of a copper wire at a given temperature.

The measurand does not need to be measured directly; it can also be indirectly determined by means of known physical or specified mathematical relationships from between the various quantities (measured values) under measurement.

A distinction is made between dimensionless measurands such as the angle, whose values are measured directly as rational numbers, and dimensioned measurands such as density, whose values are comparable to the values of the same dimension. This comparability is expressed by specifying the value of a dimensioned measurand as a multiple of the relevant measurement unit.