Theory and Practice of Temperature Measurement by Thermoelectric Transducers

Abstract

Temperature is one of the main parameters that determine the quantitative and qualitative indicators of products. Therefore, it is difficult to name a field of technology or a branch of industry where it would not be necessary to measure the temperature of solid, liquid, or gaseous substances. Along with this, it should be noted that in each specific field, the choice of methods and means of temperature measurement is determined by its specificity, which is related to the variety of technological objects, the nature of the process, the physical and chemical characteristics of the environment under investigation, the range of measured temperatures, the requirements for the necessary measurement errors, etc. Therefore, choosing a measurement method for a specific technological object is a difficult task, since it is necessary to take into account a large number of factors that can quite often be contradictory. Thus, liquid-in-glass thermometers make it possible to measure the temperature directly near the technological objects. With the help of manometric thermometers, it is possible to measure the temperature at some distance from the research objects. It should also be noted that such thermometers must be constantly connected to the primary transducer by a connecting capillary. Unlike the above, electric thermometers allow for remote temperature measurements at any distance between the primary transducer and the secondary device. Thermoelectric transducers (thermocouples) and resistance thermotransducers have become the most widely used electric thermometers for industrial applications. This is a review paper and contains information on the features of temperature measurement using thermoelectric transducers (thermocouples).