SCB-68 temperature jump

[jasonqi]

Hi,

I have some problems to get temperature through SCB-68. PCI-MIO was used to connect the SCB-68 to computer, and it worked good at beginning.  After one week break, the temperature begin to jump when thermocouple touch metal, and the temperature change from 30 to 500 C at room temperature. I connected five thermocouple, all value of thermocouple jump when each of them touch metal. Finally, I screw out all the thermocouple, and  use a new wire to test the temperature, and the value all so jump. Anyone know what happened? Is the SCB-68 died died?

Thank you.

[Kyle_K]

It sounds like your thermocouple is grounding to the metal it touches. Since thermocouples are electrical devices that deal in very smal voltage differences (millivolt ranges) it would not take much for grounding to occur. You should either not let the thermocouples touch metal (or any conductive surface) or purchase insulated thermocouples.

Kyle K.