COMPACT ZERO-THERMOSTAT BASED ON EFFECT OF MELTING BOUNDARY LAYER FILM Russian patent published in 2008 - IPC G01K7/02 G01K17/00 

FIELD: measuring techniques.

SUBSTANCE: zero-thermostat consists of an internal cylindrical case, made from material with high thermal conductivity, a heat insulated cylinder, joined with heat conducting linings, an outer case, a radiator, a floating device, thermo-electric module and a heating element. The cold junction of the thermoelectric module is in good thermal contact with the upper base of the internal cylindrical case, made from material with high thermal conductivity. The hot junction of the thermoelectric module is in good thermal contact with the radiator. Inside the inner case, there is distilled water, separated by the border of the solid and liquid phase section. In the liquid phase, there is a freely floating ring shaped bob, whose surface is made from material that cannot be washed by water. At the centre of the bob, there is reference junction of a differential thermocouple, which should be kept at 0°C. The reference junction of the thermocouple is fixed at the centre of the bob using two thin caproic threads, whose ends are tied to the bob itself and intersect at its centre.

EFFECT: increased accuracy of temperature control of reference junctions of differential thermocouples, longer period of continuous operation.

2 dwg