I
love the "variable precision" label of this meter!
But, I have purchased sixteen of these meters (yellow digits are by far more legible in bright light). Deviance from arrived median voltage point for 16 units (averaged) .007 + and .003 -
Measured against 30 ppm 5.000 vdc reference voltage
and .01% full-scale Manganin laboratory 100mv shunt.
Interpretation: Tolerance in VDC is tighter than Fluke 77 DMM, and any other meter I own including 5 digit DMM (which is more accurate than the Fluke to 30vdc).
This meter falls within the tolerances of the Manganin lab shunt, which itself agrees with the NIST 7 resistor decade, ultra precisison (3 ppm) reference resistance block of mine.
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Bottom line. For 5 dollars and change, you can get a NON-powered digital panel meter on eBay that can qualify any voltmeter DMM you own.
https://www.ebay.com/itm/Yellow-5-Digit-DC-0-4-3000-33-000V-Precision-Digital-Volt-meter-Voltage-Panel/162859254849?hash=item25eb2b0441:g:I-IAAOSwfVpYqlwEI have disqualified too many meters to take ANY of them for granted. Several with >+.6vdc to >.4vdc error. This is too great an error to manage batteries with.
A few meters were Harbor Freight cheapies and the not so cheapies. Some meters were from HALTED Electronics in Sta Rosa, CA. None of the Radio Shack DMMs passed. Even the Fluke is not dead on with .002 vdc error too low.
Personally I demand a max of .015 + - error DC for managing batteries.
To each their own. I consider adults wise enough to decide for themselves what kind of test equipment they need and to suffer the consequences in silence when they are wrong.
If the 5.0 digit meter shown above is of no interest then so be it. It is meant for someone else :)