Measurement of inductance and effective capacitance of a standard air capacitor

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1. The effective capacitance of standard air capacitors, owing to their self-inductance produced by their construction, is a rising function of frequency determined by Eq. (1). 2. The capacitor inductances are so small that at audio-frequencies their effective capacitance is virtually equal to their static capacitance. 3. An error in the computed value of the effective capacitance not exceeding hundredths of a percent at high frequencies can be obtained provided that the capacitor's inductance is known with an error of 10% or higher [1] and it is, therefore, only necessary to know the nominal inductance of a capacitor of a given type and its nominal capacitance in order to determine its effective capacitance. It is unnecessary to measure the inductance of each model. 4. The frequency error can be reduced by using the near-end connections of the capacitor. 5. The inductance of the capacitors remains constant right up to the capacitor's resonant frequencies and can, therefore, if required, be measured by a resonance method, in particular by means of a Q-meter. 6. Standard air capacitors, both of Soviet and foreign makes, can be used in metrological and testing practice for checking working capacitors, capacity-measuring sets and similar instruments up to frequencies of several megahertz, depending on their nominal capacitance and the tolerated error in checking.