TEMPERATURE DIFFERENCE METRE WITH THERMISTOR TRANSDUCERS

摘要

FIELD: instrument making. ^ SUBSTANCE: proposed device comprises two thermistor transducers, two current sources and ADC with external reference voltage source. Closed element of the first switch is connected with the second switch normally open element and first power source output, while normally-closed element of the second switch is connected with normally-open element of the first switch and second current source output to allow sequential connection of current sources to thermistor transducers. Extra resistor is connected to connection point of said thermistor to allow total current of both sourced to flow there through. Voltage drop at said resistor is used as ADC reference voltage which makes the sum of two sequential temperature difference measurements independent of current source instability. ^ EFFECT: higher accuracy of measurements. ^ 1 dwg