A thermostat with a stability of 10-3 degC and a temperature range of 38-44 C
Jolette van Overbeeke, Pieter Bennema · Journal of Scientific Instruments · 1966
A thermostat for studying the rate of crystal growth from a slightly supersaturated aqueous solution was designed. The solution is contained in a double-walled vessel consisting of two concentric Plexiglass cylinders. The space between these cylinders is divided (by means of a double Plexiglass spiral) into an ascending and a descending pathway, through which liquid paraffin is pumped. This liquid is held at a given temperature by means of four heaters. A thermistor connected to a bridge circuit controls the temperature of the liquid by means of a very fast and a rather slow servo-system regulating the heating energy.