I was recently in one Center for Metrology and Standardization.
While waiting for his turn to hand over the instruments for verification, he became interested in a curious cabinet, where electrical measuring instruments of the beginning and middle of the 20th century stood behind the glass.
As it turned out, the employees of the Center organized a small museum of ancient electrical measuring equipment. The most interesting thing is that all these devices are not only operational, but still successfully pass the annual metrological verification (all of them are on the balance sheet).
.No one allowed me to open the glass doors, so I had to take pictures through the glass.
Unique reference book "Electrical Measuring Instruments" 1927
Universal bridge UMV. 1948
Electrical energy meter K 10. 1937
Electric energy meter Ferranti. 1927
Resistance coil
Milliammeter AST. 1958
MSR 58 resistance magazine. 1960
Resistance coil R 322. 1971
Voltmeter M 210. 1953
Apparatus for testing current transformers ATT. 1957
Self-recording AC ammeter H 344. 1970
Tube voltmeter RVM 103. 1952