Ammeter

From GAWDAwiki

Ammeter from New York Terminal Service Plant, 250 West Thirty-first Street, New York.

An ammeter is an instrument for measuring electrical current in amperes by an indicator activated by the movement of a coil in a magnetic field or by the longitudinal expansion of a wire carrying the current. ^[1]

References

1. http://www.weldguru.com/welding-terminology.html