标准铂电阻温度计自热效应对测量结果的影响

Influence of Self-heating Effect of Standard Platinum ResistanceThermometer on Measurement Results

为了研究自热效应对标准铂电阻温度计测量结果的影响,分别从定点法和比较法两方面开展研究。针对定点法,统计中国计量科学研究院近3年检定的标准铂电阻温度计数据,计算不同温区的铂电阻温度计自热效应修正前后的测量结果并进行对比,结果表明,在溯源标准铂电阻温度计时自热效应修正与否对测量结果的影响达到了1.5 mK以上,最大达到了6 mK。针对比较法,设计了基于恒温槽的自热测量方案并进行实验,对修正自热前后温度测量结果进行对比,结果表明,自热修正与否带来的误差依然达到了1.5 mK。因此,在标准铂电阻温度计量值溯源和精密温度测量中,对测量结果进行自热修正是必要的。

In order to study the effect of self-heating on the measurement results of SPRTs,the research was carried out from the fixed-point method and the comparative method.For the fixed-point method,based on the statistics of SPRT verified by the National Institute of Metrology of China in the past three years,the measurement results of SPRT in different temperature regions before and after self-heating correction were compared.The results showed that the effect of self-heating correction on the value traceability of SPRT was more than 1.5 mK,and the maximum reached 6 mK.For comparative method,a self-heating measurement scheme based on a constant temperature bath was designed and experimented,and the temperature measurement results before and after the self-heating correction were also compared.The results showed that the deviation caused by self-heating correction still reached 1.5 mK.Therefore,it is necessary to correct the effect of self-heating in the precision temperature measurement and value traceability of SPRT.