04-26-2023 03:45 AM
Dear community,
I use a NI 9217 pluged on a compact DAQ chassis.
3 RTDs are wired to this NI 9217. Those are 3-wires RTDs. I verified that the wiring is correct, as well as the MAX configuration as 3 wires RTDs.
The RTDs are connected to the NI 9217 via extension cables and connectors.
I encounter the following issue:
when I disconnect the first RTD from its extension cable, it influences the readings values of the other RTDs (about + 20°C)
If I disconnect the 2nd or 3rd RTD, this phenomena doesn't happen (no influence on the other RTDs).
The first RTD is plugged on pins 5,6,7, the 2nd one on 9,10,11, the 3 rd one on 13,14,15.
I tried changing the NI 9217 by a new one, and the problem remains...
Any idea what is wrong ?
Thanks
04-26-2023 08:35 AM
This is known as ghosting. Try the steps in How Do I Eliminate Ghosting from My Measurements?