A Flexible Simple Thermostat for Small Objects and the Range of 100 to 400 K

Abstract
A flexible, inexpensive thermostat for the temperature range 100 to 400 K is described. Liquid nitrogen is the coolant and a gas serves as transfer medium. The temperature can be set to better than 1 K and is held there within ½ K by an electronic control system. The relatively small working volume of the order of 10 cm3 allows quick changes of temperature, a desirable feature in typical semiconductor experiments.