Prema 4000 6.5 Digit Multimeter

[BNElecEng]

Hello everyone,

I've recently bought a Prema 4000 multimeter as my first foray into the world of higher precision measurements. I'm planning to put my own version of the Mini Metrology Lab together.

I couldn't find an existing discussion about this multimeter, so I thought I'd create a new topic.

Has anyone used the Prema 4000 in the past? If so, could you tell me about your experiences with it? I'd like to find out about quirks early on if possible.

Thanks

[guido]

Seems closely related to the 5000. If you look at the manual https://prema.com/index.php/en/service-en/maintanance-of-measuring-instruments, then the schematics are for the 5000. Not sure what the difference is.

The 5000 is more common i think. I have two. Be careful with the handling. The case is bomb proof. But the ICs are in cheap sockets. One small moment of not having contact and the calibration RAM is empty (in mine 21C14 ICs, one of the three RAM chips has battery backup). I modified my meters, adding a specific IC handling the battery backup. Wiring the VCC, GND and CS direct, without using the socket. Obviously you then need to re-calibrate them.

I also changed the PS caps and replaced the chopper amp in one (it was a bit "noisy").

[BNElecEng]

Thanks for the heads up. I'll take mine apart carefully and see if anything needs to be put back into place after being shipped.

The specs on the 4000 aren't going to be winning any awards but I'm hoping it'll be a good stepping stone to more precise measurements.

If you have a rough schematic of your battery backup circuit, I'd like to see if I can make it work before I take it for calibration.

[Kleinstein]

I think I have used one of the similar looking DMMs, but can't remember the exact model.

AFIAR it was reasonable for it's time and price - I remember it was one of the cheapest 6 digit DMMs at that time (1990s). I used it extensively for thermocouples (thus low voltage) and it worked quite good, including the scanner I had inside. There seemed to be some noticeable DNL, I am not used from other DMMs : not all numbers appeared equally often, even visible from the display.