I got a problem measuring efficienty on an SMPS unit.

The meter I used was indicating about 50% which was absurd.
I brought my personal old analog meter, it said about 85% !
That's why I don't like todays's meters.


Bob Engelhardt a écrit le 08/07/2019 Ã* 16:47Â*:
If I measure a full wave voltage with a non true-RMS common variety
DMM*, will it be off by a known factor, from the true RMS value?

Or is there a rule of thumb about the error.Â* E.g., the reading will
be high by about 10%.

Thanks,
Bob

* - Extech Ex320 if it matters