Measuring HV using two resistance chains - in which one resistor is of different value so that chains are unbalanced

摘要

The voltages across the chains forming voltage dividers are measured within a short period. The voltage across the resistor of known value is switched in and the others shunted. A first voltage measurement occurs during or over a first period. In a further period the voltage is measured at a charged resistance. A switch-over can follow at the end of the first period for a definite charge. A further measuring occurs during or over another period following the next one. A phase shift of the voltages by switching in or out the resistor of known value can be taken into account in ascertaining the voltage. The resistance values of the two chains between the h.v. (1) and earth (2) differ by the resistor (RD) of known value. The latter can be bridged by a switch. ADVANTAGE - Impedance of measuring resistors is small compared with total impedance of chain.