Schering bridge

Figure 22.10. Schering bridge circuit. The capacitance being measured (the test capacitance) is represented by Cl and in series. R3 is a fixed resistance. Balance is obtained by adjustment of C3 and either Cl or R2. D is the detector.

Fig. 5.9 Circuit diagram of a shielded conjugate Schering bridge with a Wagner earth and a guarded specimen holder.

Using these techniques great precision can be achieved with a Schering bridge over all of its working range. Differences in 5 as small as 300 nrad may be resolved (Astin, 1936). 

It follows that there are two components to be balanced before the output of the bridge (across (D)) can be used to monitor the elution of a solute. Balance in the Schering bridge is achieved by the iterative adjustment of (R ) and (C). At balance the following relationships will hold ... 

Ultra-low-frequency bridge (Harris bridge) Schering bridge transformer bridge o o [Pg.231]

In the Schering Bridge, one sets the resistance ratio R1/R2 (range) and varies and Cj to obtain a balance [ASTM D150] ... 

The instruments used for the determination of dielectric constants are based on Wheatstone bridges (10-10 Hz), Schering bridges (lO" — 10 Hz), distributed circuits and time-domain spectrometers. A detailed presentation is given by Boyd (1980). 

FIGURE 11.4 Simplified Schering bridge. (Data from Bolts, S. C., and G. L. Moses, Insulation, 7, 19, December 1961.)... 

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