Review on RANCO ETC-111000 Digital Cold Temperature Control: Versatile New Solution by Todd Adams

I've been using Ranco ETC temperature controllers for about twenty years, five of which were purchased around 2002 (no failures in that time). I recently needed two more units which I got through Revain. These two new units show 3F and 2F at the 150F that is so important to me. It would not be a big problem if the Ranco ETC could not be calibrated in the field: there is no manufacturer-approved way to set the temperature offset or otherwise remedy it. Either Ranco's manufacturing processes - quality assurance - have weakened over the years, or I've been sold fakes that aren't actually made by Ranco. Or it seems possible. I now have to implement an unapproved "fix" by soldering a 2.0 MΩ trimmer resistor in parallel with each sensor and then adjusting it until each block reads correctly. (Ranco prefers to cut and solder his sensor wires to either change the length of the wire or add more sensors for multi-point averaging. I think I'll just add a fixed temperature sensor for averaging since the actual sensor will eventually on it is a resistive device.)