Okaaaay, I did
not understand how the accuracy was supposed to be calculated. It's pretty goofy the way it works. It's like there's an extra step just to confuse me. 😉
So the real accuracy is
supposed to be:
0.0040 + 0.0004 = 10 x (0.0040 / 100) + 10 x (0.0004 / 100) = +/-0.00044
.0004 + .00004 =
.00044That makes the lower number 9.99996, but that's only assuming that the calibrated reference really matches the calibrated number in his environment, which it does not, according to three 6.5 digit DMMs.
I saw
Skander's calibration post, and the Siglent was usually above the nominal value, but now it's under. That's not awesome.
However, since the meter is 6 years old, it's not under warranty anyway. Maybe it would be better to let an independent lab calibrate / adjust the meter?
SiglentNA quoted me $300 just to calibrate. Trescal told me $200, and a couple smaller but still certified/traceable labs quoted me around there, including the data. I would rather an independent lab calibrate it anyway; I would certainly never pay the manufacturer extra for a potentially biases cal. 😉
I would still like to see longer data after everything is properly warmed up.