Calibrating a cheapo DMM?

I've got 2 cheapos that don't give the same reading. Both have trimpots inside

what's a good way to calibrate them?

i'm thinking that a computer motherboard would have some pretty accurate voltage references right?

Better buy real but budget reference voltage check boards. http://www.voltagestandard.com/

Any suggested budget-level voltage check boards that can ship internationally, maybe someone has tested anything from AliExpress?

My Mastech MS8229 multimeter generally gives readings about 0.02v higher than from the SkyRC MC3000 (which I would think is the more accurate reading of the two).

Dont know about ali but on e-bay do search "Precision Voltage Reference Module Ad584kh" or just Ad584kh Bretty old thread (not in BL forum) about it https://goo.gl/fPyhNW

I’ve got two boards that I often use as voltage reference…

The first one is an kkmoon box, I think it was around $17 from Amazon.

The other one is an Adafruit board… about $8 from eBay…

I found this.

So he is using an AA alkaline battery as voltage reference? Umm… ok. :person_facepalming:

That’s part 1 check out part 2 ( I can’t get the link to work) anyhoo he says he’s got hold of two fluke meters & they both say the voltage is 1.619.