THERMOSTAT calibration and validation of oceanographic instruments

摘要

FIELD: physics; control.;SUBSTANCE: invention relates to a thermostat for calibrating and checking oceanographic tools. Disclosed is a thermostat, having a working heat-insulated chamber and a Peltier cooling element with a fan placed in said chamber, connected to directly to a stabilised power supply, a resistive heating element which is controlled by an actuating switch in form of a power transistor, and an electronic temperature controller consisting of a bridge circuit with a sensor and a temperature setter, with a bridge imbalance amplifier, wherein the electronic temperature controller further includes a unit for smooth adjustment of heater power and a unit for alerting on/off switching of the heating element connected in series between the bridge circuit and the input of the power transistor, wherein the unit for alerting on/off switching of the heating element is based on an operational amplifier with a differentiating RC circuit in the inverting feedback of the operational amplifier, and the unit for smooth adjustment of the power of the heating element is in form of a sawtooth-voltage generator with controlled cutoff threshold, built from two OR logic elements with an integrating RC circuit at the output of the generator.;EFFECT: increasing accuracy of temperature control to 0,001°C and cutting the time it takes for the thermostat to reach a given temperature three-fold by optimising the control algorithm.;1 dwg