Multimeters
Thought I would test a greenlee clamp on multimeter that I bought at a rummage sale. The greenlee read 123 volts. The fluke I have is quite old and read 119 volts. The harbor freight cheapie I hav...
Forum Discussion
From downloaded manuals, the AC voltage accuracy spec of the HF meters is probably either 1.2%+5D or 1.2%+10D. That's either about 1.94 volts or 2.44 volts. Just for curiosity I tested a few HF meters I have lying around.
My most trusted meter varied 123.0 to 123.2 during the testing.
A low-end Sears clamp meter varied 122.6 to 122.8 (about 1/3% difference).
HF #1 - 123.1 to 123.6
HF #2 - 123.1 to 123.8
HF #3 - 121.6 to 122.0
HF #4 - 123.0 to 123.4
HF #5 - 121.4 to 122.5
So if one assumes the 'trusted' meter is correct, the HF meters are all within their spec. It would take a reading below about 121.0 to be out-of-spec. The 4 volt spread the OP saw does look bad.
My most trusted meter varied 123.0 to 123.2 during the testing.
A low-end Sears clamp meter varied 122.6 to 122.8 (about 1/3% difference).
HF #1 - 123.1 to 123.6
HF #2 - 123.1 to 123.8
HF #3 - 121.6 to 122.0
HF #4 - 123.0 to 123.4
HF #5 - 121.4 to 122.5
So if one assumes the 'trusted' meter is correct, the HF meters are all within their spec. It would take a reading below about 121.0 to be out-of-spec. The 4 volt spread the OP saw does look bad.
