Dr. Frank, Dcac; joeqsmith, Sleppy et al:
I bought a 121GW that I received about a week ago. Today I noticed unusually poor capacitor readings (FW 2.02); now finding this capacitance discussion, I'm having buyer's remorse.
A 100 pf cap in my meter for several hours drifted only 1-2 pf, so drift isn't the issue. But at 67 pf, it's just way off.
Reading between the lines, perhaps, I get the impression that it will not be possible to get reasonable sub-100 pf readings. Since most of my work is 'portable', I do not want to drag a $10 meter along as a fix.
I'm not thrilled by the prospect of re-engineering the meter I bought to do work, nor am I qualified to do so.
What's your best suggestion?
Fabrice
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I can't recalibrate ... for some reason using a 10nF like in instructions result in 0.000nF readings in this range for any cap , so the only option is to reload the saved calibration . Maybe it's a bug , I tried many times even with different values , I don't think I did something wrong
Also pay attention if you try to re-calibrate the capacitance ranges.
There is no entry for zero value calibration in the small table inside the chapter ZERO OFFSET CALIBRATION.
In the big colored table, though, there is a scrambled entry, 'R1 : ', which might indicate that the first calibration point with open leads sets the offset, and the 2nd one with the nominal reference capacitor sets the gain.
That might explain CDaniels problem, that 0.000 is displayed for a 10nF capacitor, after calibration.
Frank
I'm not sure if the capacitance calibration procedure ever been properly documented, I can't find it anyway, but here is what worked for me:
First make sure...