Metrawatt Metrahit 14S Multimeter ... how to calibrate Ohm range ?

[KlausF]

Hello

I sought the EEVBlog forum and googled, but no matches found.

I would like to adjust (calibrate) the Ohm range of a Metrawatt Metrahit 14S  (multimeter).

Now I am searching for schematics, service manual or instruction how to do that.

Any help welcome. Thanks.

[nsrmagazin]

Why do you think its calibratable. I found this manual, but I don't see calibration possibilities.

https://www.utwente.nl/en/tnw/slt/documentation/Equipment/GeneralEquipment/metrahit18s.pdf

[2N3055]

datasheet:

Calibration
The multimeters of the METRAHit S series can be calibrated automatically via the RS-232 data interface with the aid of the multifunction calibrator METRAtop 90C and the METRAwin 91 software.

Gossen doesn't publish calibration procedures, and you need RS232 cable. That's bad news. Good news is that in Germany you should be able to find a company that is able to professionally calibrate it. Trick is to get them to do it cheaply.

If you don't mind me asking, why do you want to calibrate it? They are good quality instruments, they don't drift that easy. If you verified it gives incorrect readings, it is more probable it was damaged than drifted if error is large. So you would first have to repair it before checking accuracy any further ...

[KlausF]

Why do you think its calibratable. I found this manual, but I don't see calibration possibilities.

https://www.utwente.nl/en/tnw/slt/documentation/Equipment/GeneralEquipment/metrahit18s.pdf

That is nothing unusual. Instruction manuals rarely comprise calibration procedures. That is why I asked for schematics / service manual.

[KlausF]

datasheet:

Calibration
The multimeters of the METRAHit S series can be calibrated automatically via the RS-232 data interface with the aid of the multifunction calibrator METRAtop 90C and the METRAwin 91 software.

Gossen doesn't publish calibration procedures, and you need RS232 cable. That's bad news. Good news is that in Germany you should be able to find a company that is able to professionally calibrate it. Trick is to get them to do it cheaply.

If you don't mind me asking, why do you want to calibrate it? They are good quality instruments, they don't drift that easy. If you verified it gives incorrect readings, it is more probable it was damaged than drifted if error is large. So you would first have to repair it before checking accuracy any further ...

Metrawatt is one of the high-end manufacturers with highest quality instruments.

I asked for service manual / schematics because I got me a used Metrahit 14S and I want to profoundly check it and if necessary calibrate it.

Nobody having schematics or service manual ?

[RobinLox]

This meter gets calibrated just by some potentiometers. The 12S-16S share a very similar PCB. The 18S is the only 1xS series model which gets calibrated electronically.

You could try to identify the correct pot by following the traces on the board.