High-temperature temperature sensor TXA-210, TXK-210

High-temperature temperature sensor TXA-210, TXK-210 (thermocouple, thermoelectric converter, temperature sensor) is used in many industries for measuring the temperature of air, exhaust gases and their combustion products, and other chemically non-aggressive media in the temperature range from -40 to 1000 °C.

The range of temperatures measured by the sensors directly depends on the chemical composition of the measuring element. The main measuring element of such sensors is a segment of thermoelectrode wire sequentially connected from two dissimilar electrically conductive metals, called a "thermocouple." According to its purpose and design, a thermocouple can be immersion or surface, hermetic or non-hermetic (with or without a sheath), shock-resistant, stationary, portable, etc.

Features:

• Has low thermal inertia indicators.
• Short-term operation of sensors is possible at 1100 °C.
• Since the protective beads are made of ceramics, care must be taken during installation and operation to avoid impacts on the thermotransducer.
• Not used for measuring the temperature of liquids, melts containing nitric acid and nitrates, and should not be applied in atmospheres with increased sulfur and ammonia content.

Type characteristics:

• TXA - K -40..1000 °C
• TXK - L -40..600 °C
• TZHK - J -40..600 °C

Type K (chromel-alumel thermocouple):

• Widely used in various fields from -100 °C to +1000 °C (recommended limit depends on the diameter of the thermoelectrode);
• In the range from 200 to 500 °C, a hysteresis effect occurs, i.e. readings during heating and cooling may differ. Sometimes the difference reaches 5 °C;
• Used in neutral atmosphere or atmosphere with excess oxygen;
• Readings decrease after thermal aging;
• Not recommended for use in rarefied atmosphere because chromium can precipitate from Ni-alloy (so-called migration), the thermocouple then changes EMF and shows underestimated temperature;
• Sulfur atmosphere is harmful to the thermocouple as it affects both electrodes.

Type J (iron-constantan thermocouple):

• Not recommended for use below 0 °C because condensation of moisture on the iron lead leads to rust formation;
• The most suitable type for rarefied atmosphere;
• Maximum operating temperature is 500 °C, since above this temperature rapid oxidation of leads occurs. Both leads quickly deteriorate in sulfur atmosphere;
• Readings increase after thermal aging;
• Advantage is low cost.

Accuracy class:

• TXA - 1,2,3
• TXK - 2,3
• TZHK - 1,2

Possible version with terminal block TXA-210k