Can I use an IR sensor with NI-9213?

[AC_DeWitt]

I am using an Exergen IRt/c.3AMF-HiE sensor to monitor a liquid

http://www.exergen.com/industrial/PDFs/adjustable3amf.pdf

The sensor will be used outside its normal operating range (liquid temp = 37C), so its output sensitivity will be roughly 1/3 that of a normal type-J thermocouple (0.019mV/degC instead of 0.055 mV/degC). It will need CJC, so I would like to use an NI-9213 for signal conditioning. I need to detect temp changes of 0.2C. If I use the high-resolution mode on the 9213, I should be able to detect 0.2C changes (sensitivity spec = 0.02 x3 = 0.06 for IR sensor). Is  this correct?

[_enigma_]

AC DeWitt,

In theory, you could use the NI-9213 measure any voltage within the input voltage limitations.  Applying CJC and Thermocouple calibrations is where you may run into trouble.  The CJC setup & calibration is based upon thermocouple inputs, so you would essentially need the IR sensor to 'mimic' a thermocouple upon input.  Assuming you could calibrate the IR sensor against thermocouple perfomance, theoretically you should be fine.

It's a hands on world, plug it in and test it out.  Make sure to stay inside the voltage limitations of the device.

Regards,

Alexander M

Applications Engineer

National Instruments

[Craig_D]

I'm not very familiar with those sensors, but from what I gather, the output can be treated as a thermocouple. In that case, from the 9213 manual (on the product page under the resources tab):

Measurement sensitivity

High-resolution mode

Types J, K, T, E, N ...............<0.02 °C

Types B, R, S ....................... <0.15 °C

We also have a higher accuracy model, the 9214, which from the manual has these sensitivity specs:
Measurement sensitivity

High-resolution mode

Types J, K, T, E, N ...............0.01 °C

Types R, S ............................ 0.03 °C

Type B.................................. 0.04 °

[AC_DeWitt]

Thanks for the advice. I'm going to give it a shot, per your suggestion - I just wanted to make sure there weren't any showstoppers. I will be doing independent cal, so I should be able to work around the issues you mention. Thanks!