Industrial application requires Pt100 platinum resistor temperature measurement system has high precision

large range

low temperature drift

low power consumption

low cost. On the basis of analyzing and correcting theoretical error of the existing temperature measurement circuit

a three-wire Pt100 temperature measurement system based on MSP430 is introduced

in which

constant current source is used as standard working current

and the wire error is eliminated by proportional subtraction circuit. The 16-bit ADC inside MSP430 and outer reference voltage are used to aquire signal. Combined with the look-up table method

the primary interpolation method and smoothing filtering algorithm

finally the accurate temperature is obtained. Software simulation and physical verification shows that the system has high precision in measuring range

low temperature drift in working temperature range

low power consumption and low cost

it meets the industrial field requirements.