多路铂电阻测温系统设计

薄膜铂电阻在温度测量领域应用日益广泛,但由于自热效应等特性影响导致实际测量准确度不高,因而结合多点测温的实际需求,提出通过控制流过铂电阻电流的时间方法,保证了铂电阻与被测环境温度保持一致,消除了自热效应影响。主要设计实现以C8051F350为主控制器的电流切换控制电路和信号采集电路,通过计算系统在标准温度点测量值的重复性指标和比较多路测量结果的一致性对性能进行了验证,结果表明设计的系统性能稳定,采集精度高。该方法为薄膜铂电阻应用于高精度温度测量领域提供了有益参考。

Design of multi-channel temperature teasurement system based on platinum resistance thermomers

The thin-film platinum resistance thermometers are widely used as the precision measuring sensors in thermometry. But the charactor of the self-heating effect reduces the accuracy. In order to make sure the high precision of multi-point temperature measurement,a new method is proposed in this paper. By the method of controlling power supply time of PRT, PRT keep consistent with the ambient temperature. The current control circuit and signal acquisition circuit were designed, performance was demonstrated by computering the repetitiveness of fixed temperature. The test results show that this system is credible and stable. This method provides helpful reference to the application of PRT in high-precision temperature measurement.