Temperature sensors TSM-204, TSP-204, TXA-204, TXK-204, TZHK-204 group 2 are designed for measuring the temperature of the surface of solid bodies in various industries. They have small dimensions, improved thermal inertia characteristics, and do not require complex installation works when mounted on site. Temperature is the most common measured parameter, and overheating is one of the most negative factors in equipment operation, so there are many ways and places to apply temperature sensors. The operating principle of resistance temperature detectors is based on the change of electrical resistance of conductors and semiconductors depending on temperature. The material used for such a sensor should have a high temperature coefficient of resistance, preferably a linear dependence of resistance on temperature, good reproducibility of properties, and inertness to environmental influences. Platinum meets all these requirements the best; copper somewhat less. Thermocouples are exclusively differential temperature sensors. They generate an electrical signal proportional to the temperature difference between two different points. Therefore, the junction (weld) where the required temperature is measured is called the “hot” junction, and the other junction (which cannot be avoided) is the “cold” junction. Classification of TSM-204, TSP-204, TXA-204, TXK-204, TZHK-204 temperature sensors by type of sensing element Resistance temperature detectors (thermometers) - TSM, TSP; Thermoelectric converters (thermocouples) - TXA, TXK, TZHK; Semiconductor converters - TP. Main technical characteristics of TSM-204, TSP-204, TXA-204, TXK-204, TZHK-204 temperature sensors: Connection scheme of sensing element (SE) - two-, three-, four-wire; By SE type divided into: Resistance temperature detectors (RTD, thermometer, temperature sensors) (50M, 100M, 50P, 100P, Pt100, Pt500, Pt1000, Pt2000, Pt10000); Thermoelectric converters (TC, thermocouples, temperature sensors) (TXA (K), TXK (L)); Semiconductor (DS18B20); Degree of protection against dust and water - IP54; Design of resistance temperature detectors (temperature sensors) - non-disassemblable; Insulation resistance - not less than 100 MOhm; Accuracy classes - A, B, C (for RTD), 1, 2 (for TC).