ABSTRACT
In the measurement of electrical impedance, the definition of the measurand plays an essential role. In metrology, the definition is the set of rules to identify in a unique way themeasurand : “...the kind of quantity, description of the state of the phenomenon, body, or substance carrying the quantity, including any relevant component...” (VIM, 2.3). The purpose of impedance definition is to define a geometrical closed surface and a set of electrical boundary conditions, in the attempt to exclude every effect of connections, cables, the meter, and electromagnetic properties of the environment, so that changes in the latter have no effect on the measurement result (VIM, 2.9).
