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I have a Digital meter and I beleive the reading for voltages is off. Is there a way to connect
the meter to a source that is very accurate so that I can set the meter right?  My mind
escapes me as to what is accurate.    Bill

[AC5E]

Hi: Accuracy is relative, of course, but fresh dry cells are pretty close to identical.

  I checked a dozen brand new AA cells and found them to read between 1.567 and 1.571 volts. If yours measures a new and fresh AA at close to 1.57 your meter is close enough for any practical purpose.

  73 Pete Allen  AC5E

 

[WB2WIK]

Some ideas:

Check the anode voltage on your color TV set...a 32" tube has ~32,000V applied, just measure it.

Okay, I'm kidding!

Pete's suggestion is good, but beware that battery voltage varies with construction as we all know, and carbon-zinc, alkaline, mercury, Ni-Cd, NiMh, etc, etc, all have different cell voltages.  I've seen brand-new, factory-fresh Duracells (and similar) measure over 1.6V, so it might depend on the exact model and materials used in that particular production run.

Here's what I'd do (honestly): Take the meter to a local electronics store that sells reasonably good test equipment, along with a battery of some sort.  Use a store sample, something good, e.g., Fluke or whatever they have, and measure the battery.  Then use your meter to measure the battery.  If yours reads differently, it probably does need calibration!  

If you're really anal about this, or have some real, serious need for your DVM to be correct, you could always rent a voltage standard, or a piece of highly accurate test equipment (like a multi-thousand dollar professional DVM), from Electro-Rent or equivalent, and use that standard to calibrate your meter.  Professional test equipment rental typically costs 10% of the cost of the equipment, though, so renting a $1000 meter could cost $100.  Might be cheaper to toss it and buy a new one!

73 de Steve WB2WIK/6