The trend of development of measuring equipment in particular measuring systems and technological processes leads to the need of measuring the temperature without dismantling the primary transducers and stopping the technological process in a very wide range and with high accuracy. The choice of methods and means of measurement depends on such factors as the value of measured temperature, necessary accuracy of measurement, conditions of measurements, and operation of the investigated object. The topicality of the problem is that industrial metrology operates the temperature measuring systems, transducers of which
are deployed in such a way that their dismantling is impossible due to the specifics of the process or dangerous for operators’ life (nuclear power plants). Such measuring systems, due to the specifics of their application, are not metrologically provided in the periods between major repairs of controlled objects, thus violating the unity of measurements.
