A non-unique evaluation method for thermometer

Abstract

The invention relates to a non-unique evaluation method of a thermometer. The resistance value of the thermometer when the standard resistance is Rs; after that, connect the Rs end of the precision bridge to a thermometer, connect the Rt end to the remaining thermometers respectively, and measure the corresponding resistance values ​​of these thermometers under the Rs; complete a round After at most multiple cycles, calculate the average value of all the resistance values ​​measured by each thermometer as the thermometer under test as the resistance value of the thermometer, use the ITS-90 temperature scale to convert the resistance value into a temperature, and compare the temperature differences of each thermometer to achieve the temperature Non-unique measurements of lower thermometers.

Description

technical field [0001] The invention belongs to the field of measurement and detection, in particular to a non-unique evaluation method for thermometers. Background technique [0002] The 90 international temperature scale is defined by a series of metal and non-metal pure substances as fixed points, and the value transfer is realized through interpolation instruments (standard thermometers) and interpolation equations. For a specific temperature sub-range, when different thermometers of the same type are used to measure the same temperature, due to the influence of many factors such as platinum resistance materials or other inherent differences in different thermometers, when the thermometer is used for high-precision measurement, even the same For the type of thermometer, the actual measured temperature value will also have certain differences, which will bring uncertainty to the transmission of the temperature value beyond the fixed point. This phenomenon is called the no...

AI Technical Summary

Problems solved by technology

For a specific temperature sub-range, when different thermometers of the same type are used to measure the same temperature, due to the influence of many factors such as platinum resistance materials or other inherent differences in different thermometers, when the thermometer is used for high-precision measurement, even the same For the type of thermometer, the actual measured temperature value will also have certain differences, which will bring uncertainty to the transmission of the temperature value beyond the fixed point. This phenomenon is called the non-uniqueness of different thermometers for the same temperature measurement. , the so-called non-uniqueness has become one of the largest sources of uncertainty in the sub-ranges of most standard platinum resistance thermometers; in addition, due to the difficulty of obtaining a stable constant temperature environment close to the fixed point level, it also brings a great deal of uncertainty to the measurement of non-uniqueness. difficulty

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