The measurement method is the way in which a measurement
is carried out. The measurement method is independent of the measurement principle and describes the procedure for the measurement. This includes the prior zero adjustment and the end range adjustment. Measurement methods are divided into direct and indirect measurement methods. The direct measurement method relies on the direct comparison of the physical measurand with a corresponding physical measurement standard. For example, if the measurement is a voltage measurement
, the reference standard is a voltage standard. In contrast, the indirect measurement method compares the physical measurand to be measured with an auxiliary quantity that corresponds to the physical quantity. For a voltage measurement, a resistance standard could be used as a reference. There are several measurement methods. The more common ones include the difference method, the compensation method, and the substitution method. While the difference method determines the deviation of the measurand to be determined from an accurate reference, the compensation method compensates the measurand with a counterpart quantity. If both quantities are equal, the compensation quantity corresponds to the measured quantity.