04-27-2010 12:54 PM
Solved! Go to Solution.
04-27-2010 01:04 PM
04-27-2010 01:07 PM
04-27-2010 01:52 PM
04-27-2010 02:37 PM
If that thing is just an analog input module, you'll never read a bimetallic sensor voltage reliably. You need a thermocouple amplifier ("thermocouple input module" in NI-speak).
BTW, Isn't CJC indicative of an actual sensor on the cold end and not just a constant value?
04-28-2010 09:56 AM
04-28-2010 10:52 AM
Yes, the Cold Junction Compensation sensor is an active measurement. Each dissimilar metal interface produces a voltage, including where the thermocouple wires meet the DAQ connector. However, if you know the temperature and metals of a junction you can factor this out and know the voltage at the thermocouple tip; hence the need for a sensor at (though in reality it is just near, and the environment around it is assumed to be consistent) the DAQ connector.
04-28-2010 01:35 PM
04-28-2010 02:15 PM
What's the problem with plain AI? An oversampled 16 bit AI works fine with a TC.
Randy