thermocouple and scb 100

[soleater]

"I am using the PCI 6031E connected to the SCB 100 to measure thermocouple temperatures. When I try to measure my CJC ambient temperature (channel 0), I get a value that never rises above 0.3. This is obviously too small. Furthermore, if I try to connect a K-type thermocouple to screw terminals 1 and 2 (I guess this is channel 1), the temperature reading is out of range (about 3321.23). Can someone please help me with this. I am using units of Deg C, differential mode (what the card is in), and have selected the built in option for the CJC source. Thank you in advance."

[dan bookwalter]

what volyage ranges are you trying to read the CJC and TC channels with ?? trying bumping the CJC up to .5 and your TC to a smaller range.

Dan

[soleater]

For the CJC sensor, I use the voltage option under the sensor menu. The voltage output by the CJC seems to be the correct temperature but not to scale (.2456 C instead of 24.56 C). I am using a range of 0 C to 100 C.
As for the TC, I use the K-type thermocouple option under the sensor menu and the 0-100 C range. The problem is I have the wires connected to the first two screw terminals. Therefore, I would think to select channel one in MAX when I configure it. But, I'm not sure if this is correct.

[dan bookwalter]

Do you have the dip switches on the SCB-100 set so that the CJC is on differential channel 0 ?? if so then your TC needs to be connected to 5&6 which on my DAQ cards correlates to channel 1. connect the yellow lead to 5 and the red one to 6 and give it a try

Dan

[soleater]

Thanks, it worked like a charm.

[dan bookwalter]

No problem....

good luck and have fun

Dan

[soleater]

I've encountered another problem. I test run the thermocouple and it seems to work fine. The problem comes when I try to run a task. The thermocouple is not graphed while the CJC sensor is. When I export the data, there is temperature data for the CJC sensor, but the thermocouple readings all
give "-1.#INF" instead of temperatures. Can you help me with this? Thanks in advance.