Thermocouple&RTD Knowledge

Selection of thermocouple protection tube in different temperatures

Selection of thermocouple protection tube in different temperatures?When performing temperature measurement, the thermal resistance is generally followed in the low temperature environment, and the thermocouple sensor is used in the high temperature environment. Within 500 °C, the thermal resistance temperature is accurate and the price is cheap. When it is higher than 500 °C, the thermocouple temperature is measured as Accurate, so what kind of protective tube is used?
    At 500-800°C, K-type thermocouples and J-type thermocouples are good, and there are many choices for thermocouple protection tubes, such as 304 stainless steel and 321 stainless steel. If the measurement temperature is corrosive in the atmosphere, you can choose to use 316 or 316L stainless steel.
    At 800-1050 ℃, this is high temperature, usually choose 304 stainless steel or 2520 stainless steel (310s), the highest 2520 stainless steel resistance to 1050 degrees, it is austenitic stainless steel, chrome nickel has good oxidation resistance, corrosion resistance, due to The ratio of chromium and nickel is high, the creep strength of 310s itself can continuously measure the temperature at high temperature, it has good high temperature resistance, economical price and high cost performance.
    When the temperature is above 1000℃ for a long time, ordinary stainless steel has been difficult to withstand high temperature, so two alloy materials are recommended, which are also the highest temperature applications. GH3030 can withstand 1100℃, GH3039 can withstand 1300℃, both are nickel-based alloy materials, high temperature Corrosion resistance is also very good. Above 1300°C, when the alloy or stainless steel material is sufficiently hard, ceramic materials are used at most, and the more extensive are high aluminum tubes and corundum, which can withstand up to 1600°C. In the range of 1300-1600 ℃, corundum tube is widely used, and some even design double-layer corundum tube, this is to extend the service life of the thermocouple protective sleeve in high temperature environment. Other commonly used thermocouple protection tube materials.


Contact: Mr Li

Phone: +86-18226665885

Tel: +86-0550-7788337


Add: No.20# RenHe South Road,TianChang,AnHui Province,China

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