The Schering bridge is an electrical circuit used for measuring the insulating properties of electrical cables and equipment. It is an AC bridge circuit, developed by Harald Schering. It has the advantage that the balance equation is independent of frequency. The connections of the Schering bridge under balance conditions are shown in the figure below.
In this diagram:
C 1 = {\displaystyle C_{1}=~} capacitor whose capacitance is to be determined,
R 1 = {\displaystyle R_{1}=~} a series resistance representing the loss in the capacitor C 1 , {\displaystyle C_{1},}
C 2 = {\displaystyle C_{2}=~} a standard capacitor,
R 3 = {\displaystyle R_{3}=~} a variable non-inductive resistance,
C 4 = {\displaystyle C_{4}=~} a variable capacitor,
R 4 = {\displaystyle R_{4}=~} a non-inductive resistance in parallel with the variable capacitor C 4 . {\displaystyle C_{4}.}
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