Old Weston Voltmeter

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Ron E

Ron E

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Joined 2002
#1
I have an old Weston Voltmeter, a model 341. I am guessing the date around 1940 or so. I bought it (~$10) mainly because it looks neat, maybe to put on a curio shelf or into some sort of mad scientist display.
High Frequency Voltmeter up to 30 volts Equipment Weston Ele

Mine has 2 ranges, 7.5 and 15V and is incomplete: the top, clasp, handle and hinges have been removed as it was probably built into a display or instrument or something where those were not needed.

It seems to function, but reads the wrong voltage. I opened up the back and there seem to be hand wound wirewound resistors on cards inside. I have read that these can go bad.
http://www.richardsradios.co.uk/weston type 341meter.html
Is any inaccuracy likely to be in these rather than in the galvanometer itself? Do the movement's magnets discharge over time at all?

Edit: I am not looking for knee-jerk posts by people who know nothing about these meters, which were some of the best that could be bought back then. I am curious to know mainly if the galvanometer is likely to be a source of the issue before tearing into it further.
 
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#3
Ron E said:
I have an old Weston Voltmeter, a model 341. I am guessing the date around 1940 or so. I bought it (~$10) mainly because it looks neat, maybe to put on a curio shelf or into some sort of mad scientist display.
High Frequency Voltmeter up to 30 volts Equipment Weston Ele

Mine has 2 ranges, 7.5 and 15V and is incomplete: the top, clasp, handle and hinges have been removed as it was probably built into a display or instrument or something where those were not needed.

It seems to function, but reads the wrong voltage. I opened up the back and there seem to be hand wound wirewound resistors on cards inside. I have read that these can go bad. Is any inaccuracy likely to be in these rather than in the galvanometer itself? Do the movement's magnets discharge over time at all?
Click to expand...

I have several dozen Weston meters dating back to 1898 (scale hand drawn with quill pen) the good ones still read within 1% even though they were last calibrated 60yr. ago. Aging of components is extremely unlikely. The power meters and electrostatic voltmeters are magnificent pieces of engineering worthy of displaying in a clear case even though you lose the antique value. When I unpack I could send a scan of their catalog describing how they all work.
 
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