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For capacitors in series

1 1 1 1
   ... (1.4)
C C C C
1 2 n

2. The Sauty Bridge

The Sauty bridge provides a very simple method to measure the
unknown capacitor C by comparing it with another known (standard)
x
capacitance C (Fig. 2.1). As the condenser passes only the alternating
0
current that’s why the source of such current is used in Sauty bridge.

Points A and B are connected by a slide wire (rheochord). Lengthways
by this wire slides contact D. The alternating voltage is applied
between points E and D

Moving the sliding contact D, we can receive the electrical
balance of Sauty bridge, i.e. the potential difference between points A
and B is zero therefore the null-detector (N.D.) indicates zero as well.

Such an electrical balance is performed under the following condition

Figure 2.1

C l
X
 2 (2.1)
C 0 l 1

where l  AD, l  DB are the lengths of sections of the slide
1 2
wire at the state of balance of Sauty bridge.

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