MEASUREMENT OF POTENTIAL DIFFERENCE 283 



coils at C, which are in series with the connection to the potenti- 

 ometer proper. When currents are measured, ballast coils are 



THEORETICAL DIAGRAM 



Stg.Cell 



DIAGRAM OF ACTUAL CONNECTIONS 



FIG. 162. Diagram of connections of Brooks deflectional potentiometer. 



also used. They are mounted in the case of the instrument, and 

 are shown at C in Fig. 162. 



