The Standard Electrical Dictionary

1. Galvanometer, Differential

   A galvanometer in which the needle is acted on by two coils wound in opposition, each of equal deflecting action and of equal resistance. If a current is divided between two branches or parallel conductors, each including one of the coils, when the needle points to zero the resistances of the two branches will bc equal. In the cut, C C' represent the coils, and A and B the two leads into which the circuit, P Q, is divided.