Title :
Calculated frequency behaviour of the PTB calculable capacitor in audio frequency range
Author :
Homklintian, M. ; Funck, T. ; Melcher, J. ; Bachmair, H.
Author_Institution :
Nat. Inst. of Metrol. (Thailand), Pratumthani, Thailand
Abstract :
A determination of the frequency behaviour of the PTB calculable capacitor in the audio frequency range is carried out by applying an equivalent circuit model. The circuit model considers the influence of distributed admittances and impedances within the calculable capacitor and has been derived from the main currents flowing inside the calculable capacitor and the voltage drops caused by these currents. It has been found that the frequency dependence of the cross capacitance is proportional to the square of the frequency, whereby mutual inductances of opposite electrodes and capacitances to ground dominate the behaviour at higher frequencies. At a frequency of 1592 Hz, the correction of the PTB calculable capacitor with a value of 1 pF amounts to 9.2×10-8 pF with an expanded uncertainty (k = 2) of 3.1×10-8 pF.
Keywords :
capacitance measurement; capacitors; electric admittance; electric impedance; electric potential; equivalent circuits; frequency estimation; inductance; measurement uncertainty; PTB calculable capacitor; audio frequency range; capacitance; distributed admittance; distributed impedance; electrodes; equivalent circuit model; expanded uncertainty; frequency 1592 Hz; frequency behaviour determination; mutual inductance; voltage drop; Capacitance; Capacitors; Electrodes; Equivalent circuits; Integrated circuit modeling; Standards; Uncertainty; Calculable capacitor; frequency dependence;
Conference_Titel :
Precision Electromagnetic Measurements (CPEM 2014), 2014 Conference on
Conference_Location :
Rio de Janeiro
Print_ISBN :
978-1-4799-5205-2
DOI :
10.1109/CPEM.2014.6898279