Conditioning circuit for thermistor temperature sensor with wide temperature range
At present,thermistor temperature sensor circuits generally use resistive voltage divider circuits.The nonlinear compensation temperature range is generally in the positive temperature range of 10～100 ℃,with a nonlinear error of 0.5％,some special applications require a thermistor measurement range of-45～+125 ℃.Aiming at the problem that the wider the temperature range of the thermistor temperature sensor is used,the greater the linearization error is,a conditioning circuit of thermistor temperature sensor in wide temperature range is proposed.Using precision constant current source excitation reduces self heating issues in thermistor temperature sensors.The integrated logarithmic amplifier and integrated analog multiplier are used for linearization processing.The conditioning circuit has three functions of nonlinear adjustment,zero adjustment,and full range adjustment,which can provide accurate standard voltage signals range of 0.1～4.9 V.Temperature calibration on each thermistor temperature sensor is carried out,least squares fitting according to calibration data is performed,good nonlinearity and precision indicators are achieved.The experimental results indicate that the temperature measurement range of-45～+125 ℃,the nonlinearity reaches below 0.3％,and the measurement error reaches ±0.3 ℃.
thermistortemperature sensornonlinearity errorwide temperature range
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维普
