Problem with logger.

[MarkPetrie]

Hello.

I'm using a TC-08 with 8 inputs, all type K.
ch 1 is about 800C, the others are about 11C
The readings are 250C for ch 1, 23-25 C for the other 7 channels.
If I disconnect ch1, all the other readings drop down to [the correct] 11C.
Additionally, sometimes, the readings all change to the correct ones. I haven't been able to determine a pattern for that effect.

Laptop is a PC.
Cheers
Mark

[Martyn]

It sounds as if the tip of thermocouple 1 is touching a conducting surface, and the readings return to correct values when a heater or similar switches off.

Try electrically isolating the tip.