This end is intended for immersion in liquid nitrogen. A silicon diode is imbedded in the disk for sensing the temperature of the ring assembly. Avoid thermally shocking the materials. Follow exactly the instructions for cooling down the superconductor probe. A wet probe should never be immersed in liquid nitrogen because of the possibility of destructive ice expansion between components.
Water can easily condense on the cold end of the probe.
Follow exactly the instruction for preventing this condensation. The locations of the electrical hook-up are shown in the figure. In addition, there are four adjustment potentiometers on this board. In this experiment, you might need to adjust the ZERO of the voltage amplifier and the GAIN of the diode thermometer circuit. They have been preset to assure the gain of 100 of the voltage amplifier and the calibrated temperature monitor voltage offset.