Resonant reed frequency meter

Made:
1965-1979 in United States
manufacturer:
James G Biddle Company

Resonant reed frequency meter for measuring alternating voltages in the range 45 to 55 Hz using a supply of 200-250V made by James G. Biddle Co. USA

Details

Category:
Electricity and Magnetism
Object Number:
1996-242
type:
frequency meter
credit:
Science Museum. Circulation Dept.