Hawkins Electrical Guide v. 07 (of 10) / Questions, Answers, & Illustrations, A progressive course of study for engineers, electricians, students and those desiring to acquire a working knowledge of electricity and its applications

by N. Hawkins

Ques. What is the character of the scale and how should it be constructed?

Ans. The scale is not uniform and should be hand made and calibrated under the conditions which it is to be used.

Ques. What is the objection to moving iron ammeters?

Ans. Since the coil carries the entire current they are large and expensive.

Ques. What precaution should be taken in installing moving iron ammeters?

Ans. Since gravity is the controlling force, the instrument should be carefully levelled.

Ques. Describe an inclined coil instrument.

Ans. It consists of a coil mounted at an angle to a shaft carrying the vane and pointer, as shown in fig. 2,498. A spring forms the controlling force and holds the pointer at zero when no current is flowing.