The invention relates to the field of temperature measurement systems, and provides a temperature transmission device based on a program-controlled dual constant current power supply for the technicalproblems of the existing temperature transmission device that the circuit output is not 0 and the absolute accuracy cannot reach +/-0.1 DEG C when the measured temperature is 0 DEG C. The temperaturetransmission device comprises: a thermal resistor, the resistance of the thermal resistor increasing as the temperature rises; a reference resistor, having the same resistance as the thermal resistorat 0 DEG C; two constant current sources, generating the same current, which passes through the thermal resistor and the reference resistor respectively and then is converged and grounded; a differential amplifier, two input ports of the differential amplifier being respectively connected with the current input ends of the thermal resistor and the reference resistor; an A/D converter, connected with the output port of the differential amplifier; and a microprocessor, connected with the A/D converter.

Temperature transmission device and method based on program-controlled dual constant current power supply

A RTD measurement device comprises a current splitter connected to a single current source. The current splitter splits the current from the current source into two currents and continuously monitors the two currents and adjusts them to be the same value.

Resistance temperature detection with single current source current splitter

The invention discloses a three-wire platinum thermistor PT100 temperature detection system. The system comprises a signal conditioning circuit, a C8051F350 microprocessor, an RS485(SP3082) serial communication module. A 31 pin of the C8051F350 microprocessor generates a 2.5V reference voltage source, is connected with a 1 pin of a platinum thermistor PT100 through a resistor R1, is connected with a resistor R6, a 2pin of the platinum thermistor PT100 and a 3 pin of the PT100 in sequence, and then is grounded through a resistor R2. The resistors R1 and R2 and the platinum thermistor PT100 are serially connected to form a proportional voltage division circuit. The platinum thermistor PT100 is connected into the circuit in a three wire mode. A 1 pin of J1 is connected with a reference voltage source through a resistor R1 and is connected with a 1 pin ADC converter ADC_IN1 of the C8051F350 microprocessor through a resistor R6. A 2 pin of J1 is connected with a 2 pin ADC converter ADC_IN2 of the C8051F350 microprocessor through a resistor R7. A 3 pin of J1 is connected with power supply ground through the resistor R2 and is connected with a 3 pin ADC converter ADC_IN3 of the C8051F350 microprocessor through a resistor R8. According to the invention, the detection precision is high, the interference resistance is high, the structure is simple, and the cost is low.

Three-wire platinum thermistor PT100 temperature detection system

The utility model discloses a high precision low temperature ticket thermal resistance temperature measuring circuit which comprises a three wire heating resistor PT100, a double matching constant current source, a 24 bit high precision ADC analog to digital converter and a reference resistor Rf. The three wire heating resistor PT100 is respectively electrically connected with the double matching constant current source, the differential input end of the 24 bit high precision ADC analog to digital converter, and the reference resistor Rf. The 24 bit high precision ADC analog to digital converter is respectively electrically connected with the double matching constant current source and the reference resistor Rf. The other end of the reference resistor Rf is grounded. The high precision low temperature ticket ADC analog to digital converter and the reference resistor are used, thus the temperature measuring circuit has the advantages of high measurement result precision, low temperature ticket and obvious effect.

Huang Wentong

Papers

High precision low temperature ticket thermal resistance temperature measuring circuit