一种高精度低自热多通道测温系统设计与实现

针对高精度测温系统在实现过程中受测温非线性、自热效应及热电动势等干扰源影响的问题,以阻值比较法测温电路为基础,引入序列激励电压控制抑制测温电路的自热效应及消除热电动势,并采用MSP430F149设计多通道差分放大电路。给出了系统总体设计方案,测温电路参数设计,序列激励电压控制和数字滤波补偿具体实现。测试结果表明:该系统在-40~200℃范围内,测温精度能达到±0.008℃,具有测温精度高、可靠性好等优点,可广泛应用于工业生产和军事领域的高精度测温场合。

Design and realization of a multichannel temperature measurement system of high-precison and low self-heating

Aiming at problems of nonlinearity, self-heating effect and thermal electromotive force in high-precision temperature measurement system, the driving power sequences based on the measuring circuit of resistance comparison is designed to restrain the self-heating effect and eliminate the thermal electromotive force, meanwhile design multichannel differential amplifying circuit with MSP430F149. Scheme of total design of the temperature measurement system, parameters design of temperature measuring circuit, realization of the driving power sequences and digital filtering and compensation are given. The precision of temperature measurement can reach ±0.008℃at range of -40 -200℃, and it has characters of high precision, good reliability, and can be widely used in high-precision temperature measurement of industrial production and military field.