On Monday, September 25, 2017 at 10:13:48 AM UTC-4, wrote:

If it's only marked in whole volts, reading it with accuracy won't happen, so it won't be especially accurate.

How so? I suggest that you are mistaking "accuracy" for "precision". They are not even a little bit the same thing nor follow necessarily one from another.

A gauge or meter that reads (is marked) in whole numbers but is dead-on is far more accurate than a gauge or meter marked in thousandths, but is always two units off. Although the latter meter is extremely precise.

I have a metered Iso-Variac that reads in volts measured in tens, and amps measured in tenths on a 0 -1 or 0 - 4 scale. But they are 4" meters so that even very slight needle movements are visible. The human brain is pretty good at interpolation.

Peter Wieck
Melrose Park, PA