Hello,
I have two boards PCIE-1805, I noticed that there is an offset in the measurement using Navigator and I believe that it comes from the boards. Therefore, I would like to know if It’s a known Issue / If it could be a malfunction of the boards.
I generate a voltage signal 9,9V using an AOIP CALYS 1500 with the 10V range. The signal is transmitted directly to 1805 using an ADAM-3962, a DB-62 cable and Test Leads with Banana Plugs. I have a multimeter in parallel to see if the CALYS generate the right signal and it does. I measured in differential, with channel 0&1, 2&3, 4&5, 6&7, 8&9, 10&11.
Here are the measurements I have with the 1805 channel 10&11, which has the worst measurement:
9,89221
9,88921
9,89277
9,89333
9,88996
9,88902
9,89315
9,89005
9,88827
9,8938
Average = 9,891177, We can clearly see an offset of 0,008823 V.
I have calculated the uncertainty of the complete measurement chain. I have U = 6 mV (K=3) with the following elements.
Unoise = 0,1mV
gain error = ±0,03 %
Offset error = ±1,5 mV
16 bit resolution on ±10V scale, LSB = 0,305 mV
Usource Calys = 0,78 mV
Let me know if It is coherent for you.
My measurements are clearly out of uncertainty. My DC source is up to date. I tested to change the ADAM-3962 and DB-62 cable, nothing changed.
I did the auto-calibration of the boards, nothing changed.
I have the same result with the second board.