Serial No. L128639
Cambridge sub standard ammeter Dynamometer moving coil ammeter in polished wooden case, 0-2-20 FSD Amperes AC 20-150 Hz. Working. Cambridge Instruments, Cambridge, UK. 1941
This is one of many instruments collected by Jack Davidson C Eng FIEE which I have been given by Dr Graham Winbolt
How much is it worth? Instruments such as this are of little use today and not many people seem interested in them. Expect to pay £10-£15.
I have two calibration certificates one dated 1941 and the second 1944
Instructions and calibration details on underside of lid.