Industrial platinum resistance thermometer is a widely used temperature measuring instrument. For a long time, the calculation method of CVD equation has been widely used in relevant standards or technical specifications both domestically and internationally for calibration and grading. However, industrial platinum resistance thermometers calibrated using the CVD equation have low accuracy, low stability, and high uncertainty, and cannot be used as transfer standards.
For this reason, most industrial temperature measurement fields or laboratories with low requirements can only use high-precision standard platinum resistance thermometers as traceability transfer standards. However, in the actual industrial temperature measurement field, due to various limitations, standard platinum resistance thermometers cannot be used, making it impossible to achieve temperature value transmission and traceability in these areas, and cannot carry out actual measurement calibration work.
The feasibility of calibrating and dividing industrial platinum resistance thermometers, and comparing them with the temperature resistance relationship calculation results given by the commonly used CVD equation, and then providing the differences between the two, exploring the ways and methods of establishing precision industrial platinum resistance thermometers as transfer standards. By conducting research and analysis on multiple industrial platinum thermistors manufactured by different models and manufacturers in different temperature zones, the experimental results, data curves, and measurement errors caused by using two different methods of division for each thermometer are presented.
Experimental results have shown that the interpolation method of the ITS-1990 international temperature scale is feasible for industrial platinum resistance thermometers. Compared with the calculation method of CVD equation for industrial platinum resistance calibration, it has better accuracy and consistency. Previously, the national metrology and technical institutions in Italy and Canada conducted research on the industrial platinum resistance grading method using the interpolation formula of the international temperature scale.