How do I read the CJC value on TB-2627 connected to a 2527 switch. Using a PXI-4070

[Mark88]

I'm trying to use the CJC value on the 2627 TB. The samples and the switch convert voltage to temperature value all ask for this. How do I get the actual value. I've read the white page about using it with the 2527 switch, 2627 TB and 4070 DMM. It's also advertised that it has a CJC but I can not find anywhere how to actually get this reading. I'm probably missing something simple but I could use some help. Thanks, Mark

[Blizzard]

Hi Mark88,

To use obtain your CJC value from your TB-2627, you will have to convert the thermistor voltage from the CJC into temperature. A cold-junction sensor (thermistor) is located near the J13 connector on the
PCB of the NI TB-2627. You can use the example below that converts the voltage reading to thermistor temperature in one of the VIs included in the zip file. Although it mentions the 2526, it will still work with the 2627. 

Measuring thermocouples with the NI-2527: http://www.ni.com/example/29760/en/

Additionally, you will want to follow the instructions for CJC output in the 2627 manual that I have linked below (page 11):

http://www.ni.com/pdf/manuals/374148e.pdf

Using the manual,  you can also do the calculation by hand. 

I hope this helps!

Regards,

Anna L