SYSTEM FOR CONTROL OF PRECISION NULL-THERMOSTAT Russian patent published in 2009 - IPC G01K7/02 G05D23/19 

FIELD: physics, measurement.

SUBSTANCE: invention is related to metering technology and is intended for automatic control of precision null-thermostat. System for automatic control of interphase boundary position for precision of null-thermostat is realised on three temperature detectors fixed on side wall of chamber with working substance, normalising amplifiers of signals from detectors, analog-to-digital transducers, microprocessor, digital-analog transducers, current stabilisers controlled by voltage, modules of polarity switching and two thermoelectric modules. System provides for maintenance of interphase boundary position at preset level. Float incline, as well as its freezing to solid phase of working substance are eliminated by means of current pulses passage by module for setting pulses with certain duration via induction coil fixed on side wall of chamber, which excites vibrations of coil fixed on float. Two differential thermocouples fixed on float are used to alarm about possible distortions of float.

EFFECT: increased accuracy of thermostatting and time of continuous operation.

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