Calibration of alternating voltage and alternating current involves capacitive and inductive behaviour in addition to pure ohmic resistance R. It is therefore obvious in certain cases to have one or more reference capacities and inductances for the calibration of e.g. RCL and impedance meters.
On the metrology level individual standard capacitors in the form of air and Silver mica capacitors are often used. For such capacitors not only the accuracy and stability but also the frequency behaviour is an important specification. The capacitance values also depend on the design and shape. 0.001 pF – 1000 pF, 0.001 µF (100 nF) to 1000 µF and 1 pF to 10,000 µF.
Multiple Reference Capacities are also available in decade banks.
