开云体育

I have personally never made anything like this - instead just comparing values to a 6.5 digit multimeter. But recently I bought a cheap(ish) 20,000 count Chinese multimeter, and wanted to check it. On DC around a few volts and resistance it was excellent. However, I wanted to check AC volts and amps too. That brings a whole lot of challenges. The AC mains is not stable enough, so comparing a 20,000 count multimeter with a 6.5 digit HP 3457A is totally impossible.?

I actually bought a 100 W Tandy PA amplifier from eBay, that was designed to run into 4 ohm speakers. My plan was to put that into a high voltage transformer to allow me to generate AC that should be more stable than the 50 Hz mains. Other projects go in the way, so I never got around to testing the multimeter properly on AC.?

You can expect any multimeter to be most accurate on DC voltages around its reference voltage, so most are probably going to be mist accurate on a 3 V or 10 V DC scale. To do a proper check, one really needs to test at high and low voltage DC too.?

You could consider adding AC calibration.

Fluke multifunction calibrators are extremely expensive. There’s probably a lot of work into making some produce a wide range of voltages and currents.?

Dave