Sangamo Weston Ammeters

These beautiful old ammeters are excellent examples of the finest meter movements ever made.

The scale length is 12 inches and the perfectly balanced pointers are over 9 inches from pivot to tip. A mirror scale is fitted to reduce parallex errors.

The movements employ a rectangular cross section aluminium hairspring which had to be heat treated and aged before assembly in order to minimise hysteresis and to provide minimal zero drift.

The DC ammeter is designed for use with external shunts, the basic movement being a 50 mV / 10 mA design.

The AC ammeter contains an integral current transformer and can read up to 50 amperes full-scale.

Both ammeters are in good condition and, as far as I can tell, are still within the original specification of +/- 0.1 % of full scale deflection.