by ziko » Tue Jul 13, 2010 3:13 pm
Hi this could be due to a number of reasons really:
1) The unit is faulty
2) There is a voltage being injected into the thermocouple exceeding the common mode rejection ratio of the chip.
3) Some grounding issue.
4) Faulty sensor.
How is the sensor being measured, i.e. what is it measuring and how is it placed?
Kind regards
Ziko
Technical Specialist