Process of elimination. DISCARD the far right digit altogether. It is a + - error trash can. The 2nd from the right digit can likewise be ignored - to a degree.
Buy a can of KRYLON paint ESPECALLY for plastic if you wish. BLACK works well.
Obliterate the fifth and fourth least significant digit if you must.
I have two of these meters for bench testing. They are accurate enough to be useful.
My postings of these types of goodies is not to be construed as "arm-twisting". Merely availability and perhaps good value. When I was 14 and riding fence in Montana, the line shacks had kerosene lamps and I did not have so much as a flashlight. A canvas army cot with fruit crate "foot extender" served as a bed.
I obviously believe in "Do-It-Myself" projects.
An out-of-the-box-guaranteed-accurate 3-1/2 digit LED voltmeter costs $200+ dollars. Why bother? A five-dollar meter with the two right hand most digits blocked off is just as accurate.
Parading voltage droop or incline can be a powerful trends-and-tendencies tool.
And for calibrating, only a verified accurate oscilloscope is proof-positive of accuracy of values. Over the years I have uncovered FLUKE meters that were so far out of kilter, they were a joke. My .001% accuracy decade resistor verifier is in Michoacan. Between the Tektronix and resistance verification, measurement instruments can be tested. Otherwise determining accuracy is hunch guesswork.
