Westinghouse ammeter Type PY5 Moving iron instrument for alternating current [25-135Hz]. The unit has an integral multi tap current transformer connected to front panel terminals for 5/20/50/100/200 Amps full scale deflection. Claimed accuracy is half of one percent. Westinghouse Electric & manufacturing Company, Newark New Jersey USA, date April 1944.
This is one of many instruments collected by Jack Davidson C Eng FIEE which I have been given by Dr Graham Winbolt
Close up view of scale
Interior of the instrument
Instrument with cover in place