346 



ELECTRICAL MEASUREMENTS 



The whole device is about 14 in. in diameter. The interleaving 

 of the fixed and movable coils is important for if M recedes axially 

 from one fixed coil it approaches the other, so that the net effect 

 on the inductance of a slight axial displacement of M is zero. 



K-J 



FIG. 205. Brooks variable inductor. 



The distinctive feature of this inductor is that the scale divi- 

 sions are of equal length throughout the greater part of the use- 



