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[email protected] tabbypurr@gmail.com is offline
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Default Full wave voltage reading

On Monday, 8 July 2019 18:17:32 UTC+1, Bob Engelhardt wrote:
On 7/8/2019 10:56 AM, John Robertson wrote:
...
I'd use a 'scope and do the math if the readings are critical and you
can't afford a proper AC meter


The readings aren't at all critical - a single-digit correction factor
would be good enough.

I wonder if the meter reading has a consistent relationship to the RMS
value. E.g., if the meter always used the peak value, the actual value
would simply be 0.7 the read value. If it was consistent, I could
calculate the correction factor by measuring the peak on a scope. But I
wouldn't want to have to generate correction curves.


When I looked into this decades ago, digital meters typical read the peak & reported 71% of that. So as you depart from sine, all bets are off. But as mentioned, limited frequency response also means as you depart from 50/60Hz it's all going to go out of cal.

If you're measuring a consistent waveform, eg CRT filament supply in TVs, the waveform & f are consistent so you could apply a fixed correction factor.. If your waveform or f varies, fuggedit.


NT