TCT Temperature control

The TCT apparatus has four Peltier cells inside the base. The Peltier cells themself are cooled with glyceroid fluid, which is colled down by a chiller. The cels can run up to 15V x 8A.

Inside the base there is a Pt100 sensors, which can be read by the Adafruit amplifier and digitizer and then to the Rasberry Pi.

Tests

A test has been done to understand the thermal properties and the limit of the system. Presently we are limited by the dew point, so by the humidity.

Using the values from the fit we can estimate the equilibrium temperature of the sensor (here in the next figure the temperature of the Peltier is the temperature of the fluid)

There is quite a difference if we are pumping air or not. For example, if we are pumping air, we set the chiller to -5°C and we set the voltage to 10 V we can reach around -13°C. If we don't flush the air with, with the same condition, we can go below -20°C.