DIY Cold junction Compensation on a DMM6500 - 1 Kg of copper

[Kleinstein]

The cold junction compensation is only really caring about the thermo-power from the virtual reference temperature (e.g. 0 C) and the temperature of the actual junction. Just imaging using the simulated cold junction to also measure an actual thermocouple at 0 C in parallel.
One could either use the simulation or the actual TC to 0 C.

Really important is only the thermal EMF around the cold junction temperatures, so around room temperature. The part in between is just to set the actual offset.

The piece of copper is really huge. Thermal equalization scales with the distance square, so smaller can really be faster. It should still be much faster than the water version. Symmetry can reduce the effective size to about half.

[HendriXML]

I now understand why I was wrong. One of the starting statements above was not complete:

A temperature difference results in a voltage difference, how much is dependent on the alloy
Should be
A temperature difference results in a voltage difference, how much is dependent on the alloy and the cold junction temp.

I assumed that any same temp difference would lead to the same voltage difference. But that's not the case - which seems also more logical…

To use the translation tables one needs to know the cold junction temp even for calculating a temperature difference.

[HendriXML]

The piece of copper is really huge. Thermal equalization scales with the distance square, so smaller can really be faster. It should still be much faster than the water version. Symmetry can reduce the effective size to about half.

I would like it to be smaller and of different size too, but heating up this amount may also be more fun because it asks for more max power. But as said the shape can be used to have some controlled and dampening oscillating happening in the heat up fase.