I have an 800 series dataTaker connected to four 1/10th din classB RTD's all held at the same temperature inside a Vacuum flask. When I first started logging their temperatures typical readings were as follows; ch1-4, 21.45, 21.45, 21.43, 21.37. However after logging for four days under the same conditions the readings are now; ch1-4, 23.15, 21.64, 21.64, 21.69.

To disprove any RTD error I swapped the Ch1 & Ch4 RTD's at the dataTaker and obtained the same readings. Question: Why has such a large difference in reading between Ch1 and the other channels suddenly occurred?

Good morning Max,

I contacted you via email about this.
Can you please send the results of the testing.

Thanks

Roger

Just a follow up to let people know this issue was resolved.
There was some issue with the setup.