From Friday, April 19th (11:00 PM CDT) through Saturday, April 20th (2:00 PM CDT), 2024, ni.com will undergo system upgrades that may result in temporary service interruption.
We appreciate your patience as we improve our online experience.
I have a problem reading from a TC ( K or J ) hooked to my PCI-MIO-16XE-50. I have the TC connected to channel 15 in single ended mode. The dip switches are set with the on board TC set to single ended channel 0.
If I read the Temperature with the TC laying on my benchtop then it reads correct. As soon as I connect it to my equipment which is grounded stainless steel I get huge errors. The signal seems to pickup lots of negative noise ( -200C )
I have tried to put a 4.7K ohm resistor and a small cap on the signal but no luck. Any ideas?
Thanks a bunch
If replying to my email remove nospam from the name
It's sounds like you have a problem with ground. I saw a very similar problem (although not using NI equipment). I was using a digital thermometer plugged into a wall outlet and a T thermocouple. I was trying to measure the temperature of the chassis of a piece of equipment that was grounded through a wall outlet. Whenever I touched the thermocouple to the chassis I got very wild readings. Switching the digital thermometer over to batteries fixed my problem.
I'm not familiar with the PCI-MIO-16XE-50 board and I obviously don't know anything about the equipment your trying to measure the temperature of, but it may help to take data differentially instead of single ended. If you can, you might also try shutting off the equipment and removing ground from the chassis (if it's as simple as unplugging the AC input) and retry measuring temperature. That might tell you if it's a grounding problem or not.
Doug Richardson wrote:
> Hi, > > I have a problem reading from a TC ( K or J ) hooked to my PCI-MIO-16XE-50. > I have the TC connected to channel 15 in single ended mode. The dip switches > are set with the on board TC set to single ended channel 0. > > If I read the Temperature with the TC laying on my benchtop then it reads > correct. As soon as I connect it to my equipment which is grounded stainless > steel I get huge errors. The signal seems to pickup lots of negative noise > ( -200C ) > > I have tried to put a 4.7K ohm resistor and a small cap on the signal but no > luck. > Any ideas? > > Thanks a bunch > > If replying to my email remove nospam from the name