基于恒流源的多路高精度测温仪的研究

Research on high precision multichannel thermoscope based on constant-current source

本文用精密低压差三端稳压源,并联精密电阻形成精密恒流源,通过模拟多路开关驱动多个铂电阻进行温度测量。因在线补偿模拟多路开关的通态电阻温度特性和温度变化时被测铂电阻的阻值变化对恒流源电流的影响,设计的温度测量系统精度高、稳定性好。用分段线性化的方法标定温度,精度达到±0.1°、温度稳定性为±0.05°。

This paper brings forward the precise constant-current source,which is composed of the precise different three-terminal constant-voltage source of low-voltage and the parallel precision resistance.This precise constant-current source measures temperature by simulating multi channel analog switch to drive platinum resistances.The system has high precision and stability,because the temperature property of break-over resistance of the multi channel analog switch is compensated momentarily,and the variation of platinum resistance that accompanies temperature change can influence the output of constant-current source.The method of piece-wise linearization is used to calibrate temperature.The precision of the system reaches±0.1°,and the temperature stability reaches(±0.05°.)