I will be doing the modification on a U1273AX by replacing BD4,5,7 and R55. Since I have access to a Fluke 5522A calibrator I will be experimenting with the resistance adjustment before doing a full adjustment.
Have you had a chance to look at this....pleeeeease!
I have had a chance to experiment with the calibration and I can quite safely say that all you really have to do is the following (in the same order):
- Perform a short adjustment on DC millivolts then DC volts
- Perform a zero adjustment on the ohms range (short Hi to Lo using a shorting bar and let it run through all its ranges)
- Perform a open adjustment on the ohms range
- Perform a short adjustment on the diode range
- Perform a open adjustment on al DC current ranges
You can probably skip all adjustments besides the resistance short/open adjustment and still be fine, I however did do them because of the simple standards required to perform them.
After doing this and verifying the meter everything seemed fine.
The calibration details can be found in the Keysight U1270 series service guide.