Heavy Duty Avometer Mk5

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The instrument as received appeared to be in perfect condition and unopened since the day it was made. However it refused to operate an any range and the red overload indicator could not be reset. Once opened the cause was immediately apparent as can be seen in the picture above. The meter had obviously had been dropped or suffered a severe blow sufficient to part the magnet and dial assembly from the moving coil and pole pieces. I removed the meter completely and aligned the parts as best I could but the hairspring is now distorted and although the meter deflects it reads about 60% of the correct value and the movement catches the pole pieces preventing full scale deflection.

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For further information have a look at my pages on other AVOmeters here