All about Keithley DMM7510. Bugs and features, recipes, advice, notes.

[aronake]

It seems it got removed in the updated calibration manual not to mislead people that these are the only things needed for all calibration.

Yes, indeed, this was mentioned in the old manual.

The new manual leaves some questions open.

For example, Step 2 of DC calibration mentions 100V and 1000V full range. But it does not say whether the calibration is done automatically or an external source is needed.

The manual also suggests verifying the 100V and 1000V ranges, but does not say what to do if they are outside the tolerance? Is this a malfunction?

Unfortunately, I do not know if it is possible to do partial calibration I am also interested in this question.

I have now tired to do the artefact (cal.adjust.dc) part only. And can report that it worked very well. Before adjustment my reisitance measurement was pretty far of, but max 10 PPM off for 10 to 10K range. Only things needed is a 4 wire short, 10V and 10K ohm.

I have not checked linearity of voltage yet, but will do later.

Step 2 in DC is very easy signal to generate, just leave the terminals open

And for 100V and 1000V ranges being outside specifications after an artefact calibration. There isn't really anything to do about that (maybe try to calibrate again, i doubt that makes a difference, get the DMM7510 repaired or buy a new.... or just live with the error)

I was also wrong on 7 amp needed for AC adjustment. Apparently its possible to use 2 amp (2 amp to 10 amp) instead. I should be able to manage to arrange that. Generation would not be accurate enough on its own, so will try to use 2 3458a in parallel to measure actual current.... Not sure how that will turn out though. And not sure if i feel i need super accurate AC current measurements in the 3 to 10 Amp range.

[HighVoltage]

Before adjustment my reisitance measurement was pretty far of, but max 10 PPM off for 10 to 10K range. Only things needed is a 4 wire short, 10V and 10K ohm.

I have not checked linearity of voltage yet, but will do later.

What do you mean by far of?
How far?
In what ranges?

I have two DMM7510 and I am always surprised how stable they have been over the years.
I do not see any need for adjustments at all.
Maybe I got lucky with my units.

[MegaVolt]

I have now tired to do the artefact (cal.adjust.dc) part only. And can report that it worked very well.

This is good news. Did you save the partial calibration results?

[aronake]

I have now tired to do the artefact (cal.adjust.dc) part only. And can report that it worked very well.

This is good news. Did you save the partial calibration results?

Yes! So old calibration data is gone. The DMM7510 was calibrated in a supposed to be quite OK calibration lab before it was delivered to me by the seller. I got a quite nice looking calibration certificate with measurement points. But I have always been very suspicious about the quality of the calibration. And first got my standard resistors calibrated by the national metrology lab last week, so have not know which of my 10 multimeters was more right than any other. Ill hand in my 732b this week to the national lab. Then i know more about the voltage situation once i get that back.

Even with my quick and dirty calibration the dmm7510 is very well within 24 h specification on all resistance ranges. So will do a more proper calibration and then analyse the results more in detail.

[aronake]

I was just reading though the calibration manual of DMM6500 which I also have and may want to calibrate. As is quite common for a 6.5 digit DMM each range need to be calibrated for each function. All signals must be set exactly (except for resistance). It also requires a fixed no compromise 7A 1khz AC current signal which can be difficult to generate. So a comparable nightmare to DMM7510's artefact calibration

Here for instance are the steps to calibrate open front connectors. I guess all these steps may come with some added flexibility. And would of course be automated in some script. But still.... There are equally many for short front connectors.

--Use front-terminal 4-wire open circuit setup cal.adjust.step.setup("cal_DCI_3A_zero_front")  cal.adjust.step.execute("cal_DCI_3A_zero_front")
--Use front-terminal 4-wire open circuit setup cal.adjust.step.setup("cal_DCI_1A_zero_front")  cal.adjust.step.execute("cal_DCI_1A_zero_front")
--Use front-terminal 4-wire open circuit setup cal.adjust.step.setup("cal_DCI_100mA_zero_front")  cal.adjust.step.execute("cal_DCI_100mA_zero_front")
--Use front-terminal 4-wire open circuit setup cal.adjust.step.setup("cal_DCI_10mA_zero_front")  cal.adjust.step.execute("cal_DCI_10mA_zero_front")
--Use front-terminal 4-wire open circuit setup cal.adjust.step.setup("cal_DCI_1mA_zero_front")  cal.adjust.step.execute("cal_DCI_1mA_zero_front")
--Use front-terminal 4-wire open circuit setup cal.adjust.step.setup("cal_DCI_100uA_zero_front")  cal.adjust.step.execute("cal_DCI_100uA_zero_front")
--Use front-terminal 4-wire open circuit setup cal.adjust.step.setup("cal_DCI_10uA_zero_front")  cal.adjust.step.execute("cal_DCI_10uA_zero_front")
--Use front-terminal 4-wire open circuit setup cal.adjust.step.setup("cal_DCI_DIGI_3A_zero")  cal.adjust.step.execute("cal_DCI_DIGI_3A_zero")
--Use front-terminal 4-wire open circuit setup cal.adjust.step.setup("cal_DCI_DIGI_1A_zero")  cal.adjust.step.execute("cal_DCI_DIGI_1A_zero")
--Use front-terminal 4-wire open circuit setup cal.adjust.step.setup("cal_DCI_DIGI_100mA_zero")  cal.adjust.step.execute("cal_DCI_DIGI_100mA_zero")
--Use front-terminal 4-wire open circuit setup cal.adjust.step.setup("cal_DCI_DIGI_10mA_zero")  cal.adjust.step.execute("cal_DCI_DIGI_10mA_zero")
--Use front-terminal 4-wire open circuit setup cal.adjust.step.setup("cal_DCI_DIGI_1mA_zero")  cal.adjust.step.execute("cal_DCI_DIGI_1mA_zero")
--Use front-terminal 4-wire open circuit setup cal.adjust.step.setup("cal_DCI_DIGI_100uA_zero")  cal.adjust.step.execute("cal_DCI_DIGI_100uA_zero")
--Use front-terminal 4-wire open circuit setup cal.adjust.step.setup("cal_ACI_1A_zero")  cal.adjust.step.execute("cal_ACI_1A_zero")
--Use front-terminal 4-wire open circuit setup cal.adjust.step.setup("cal_ACI_3A_zero")  cal.adjust.step.execute("cal_ACI_3A_zero")
--Use front-terminal 4-wire open circuit setup cal.adjust.step.setup("cal_4W_HiOhm_7Vref_open")  cal.adjust.step.execute("cal_4W_HiOhm_7Vref_open")
--Use front-terminal 4-wire open circuit setup cal.adjust.step.setup("cal_CAP_zero")  cal.adjust.step.execute("cal_CAP_zero")