Forced Revision DMMCheck Plus

[KungFuJosh]

Of course it is fair to say you don't want to do that work. But then I'd expect to spend a lot more than for the DMMCheck Plus. Generally in calibration you pay per point that you want measured, so if they would have to measure a few dozen points, the calibration would become a lot more expensive. The PVDS2mini (well above €200 and not currently available) might be the closest to what you want, though it may not meet your traceability requirements and the specifications like INL appear to be not very tight.

Yup. I'll probably keep it under 10 points, which shouldn't be terrible. One would hope. 😉

[J-R]

Russ/Doug/Ian could surely offer additional products but none are interested.  I think they just want a steady hobby during retirement and don't want to deal with growing into a larger business.

I think there could be a market for various divider circuits, along with a budget-friendly calibration.

The PDVS2mini actually doesn't particularly excel at mV values alone.  For example, you could only do 1.00mV, although with a calibration performed at that point you might gain one additional digit that is only 1-2 off.  Each batch sells out pretty quickly.  I think the calibration set points can be flexible, so maybe check with Ian if mV ranges could be tightened up.

After thinking about this a bit, the one device that kept coming back to mind is the Advantest R6144 which can be found in quantity on eBay for under $500, primarily from Japan.  It has gotten a varying amount of attention over the years.  It can do 1.000mV for example.  The UI is really nice and easy to use.  I can connect up a known good DMM along with an unknown DMM and run through a lot of values quickly.  Ship it out for calibration or do it yourself with a 6.5 or better DMM.  The polarity relay is a known weak point, just stick to positive values and you'll be fine.  You can expect the digit beyond what is visible to typically be around 1 digit off of zero, so for example if you select 1.000mV the actual value is typically going to be 1.0001mV, a least in my unit.  It also has a great mA source which could also be used to generate precise mV values.

[rkeller]

Is the voltage standard only ~5V? I'd love to see a standard that covers multiple ranges including mV.

What about this one:
https://voltagestandard.com/shop/ols/products/pentaref

[KungFuJosh]

Is the voltage standard only ~5V? I'd love to see a standard that covers multiple ranges including mV.

What about this one:
https://voltagestandard.com/shop/ols/products/pentaref

Thank you, but I actually have a similar one covering those ranges. However, I'm an idiot. I realized after searching for a low mV reference, that I actually need an AC reference in that range. Too much time passed, and I forgot that the issue wasn't DCV. 🙄🤣

[J-R]

Quick note, the PentaRef has reduced 6 month accuracy specs of 0.2% below 1V.  (Normal range is 0.01%-0.04%.)

A little off topic at this point I suppose, but for low mV AC, you maybe can get away with using a function gen along with a calibrated DMM.  Many of the popular cheap generators can go down to 1mVpp, for example.

[KungFuJosh]

for low mV AC, you maybe can get away with using a function gen along with a calibrated DMM.  Many of the popular cheap generators can go down to 1mVpp, for example.

That's a great idea, thanks! I have the SDG2122X. I should have thought of that lol.