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Old 13th Oct 2018, 3:15 pm   #37
G0HZU_JMR
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Join Date: Sep 2010
Location: Cheltenham, Gloucestershire, UK.
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Default Re: Full wave rectified RMS voltage

Quote:
Originally Posted by G8HQP Dave View Post
Maybe the AC coupling ought to be optional, as for oscilloscopes.
Some meters can achieve the equivalent. My old Fluke 45 bench meter can do AC Vrms (and AC Irms) and can also combine AC+DC if required. However, I never use this feature and I think that on this meter you have to avoid the 'fast' display mode when combining AC and DC. Otherwise significant errors can creep in.

I think that it measures the AC Vrms and then the average voltage and then it calculates the AC +DC based on these two measurements and sends it to the display. So it isn't a direct measurement as such. It is a built in feature that does the sums internally based on the above two measurements. To get it in this mode you have to press the ACV and DCV buttons at the same time.
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Last edited by G0HZU_JMR; 13th Oct 2018 at 3:24 pm.
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