标准铂电阻温度计W_t数学模型使用中的理论误区及新模型研讨  

Discussion on theoretical misunderstanding and new model in the use of standard platinum resistance thermometer W_t mathematical model

作　　者：陈桂生[1] 付志勇[1] 姚小兵[1] 朱育红[1] 韩志鑫[1] 杨锐[1] 冯锦[1] CHEN Guisheng;FU Zhiyong;YAO Xiaobing;ZHU Yuhong;HAN Zhixin;YANG Rui;FENG Jin(National Institute of Measurement and Testing Technology,Chengdu 610021,China)

机构地区：[1]中国测试技术研究院,四川成都610021

出　　处：《中国测试》2018年第4期1-7,共7页China Measurement & Test

摘　　要：长期以来,国内外温度计量学界对标准铂电阻温度计检定结果的不确定度使用数学模型W_t=R_t/R_(tp)进行评估。为探讨使用该数学模型的正确性,对此类温度计检定结果不确定度分量中最重要的影响量在该数学模型中的地位与影响进行分析研究。通过对误差分析、不确定度评估的结果与温度计检定中重要误差分量的图解数据比较,发现W_t公式所代表的误差(或不确定度)分量是总误差中很小的一部分,与大误差项相比几乎可以忽略不计。该结果还得到某一检定规程实际数据结果的验证,证明W_t公式作为不确定度评估的数学模型是不科学的,可能漏掉大误差项。指出按现行规程规定的温度定点分度方法,依靠W_t比值公式来规避电阻的绝对精密测量是不真实的。最后,在讨论电阻温度计检定方法与结果的基础上给出正确评估标准铂电阻温度计检定结果不确定度的数学模型。The uncertainty of calibration results of standard platinum resistance thermometer is evaluated by mathematical model Wt=RJRtp at home and abroad for a long time.To describe whether the mathematical model is correct or not,a research is carried out for the position and influence of the most important influencing component in the mathematical model among the components used for thermometer measurement results uncertainty assessment.Through comparing of graphic data of error analysis,uncertainty assessment results and important error components in thermometer verification,it is found that the error(or uncertainty)component represented by Wt formula is a small part of total errors and it can nearly be ignored when compared with large error.This result is verified by actual results in one measurement specification,proving that it is unscientific to use Wt formula as the mathematical model for uncertainty assessment as many large errors may be omitted.It is also pointed out that with the temperature point fixing and grading method regulated in existing specification,it is unreal to use Wt formula to avoid the absolute resistance precision measurement.Finally,on the basis of discussing the verification method and results of resistance thermometer,a mathematical model used for the correct assessment of the measurement results uncertainty of standard platinum resistance thermometer is given.

关 键 词：量值传递 国际温标 标准铕电阻温度计 水三相点 测量方法 误差 不确定度 

分 类 号：TH811[机械工程—仪器科学与技术]