What are the significant differences in the electromotive force-temperature characteristics of thermocouple sensors with different graduation numbers?

Material composition and thermoelectric potential coefficient:
Thermocouples with different graduation numbers in the thermocouple sensor are composed of different metal or alloy materials. The thermoelectric potential coefficients of these materials are different, resulting in different electromotive forces generated at the same temperature difference. For example, the K-type thermocouple is composed of a nickel-chromium-nickel-silicon alloy, while the J-type thermocouple is composed of an iron-constantan alloy. These different material combinations determine their own unique electromotive force-temperature characteristics.

Temperature range and sensitivity:
Thermocouples with different graduation numbers are suitable for different temperature ranges and have different sensitivities within this range. Some thermocouples (such as R-type and B-type) show higher sensitivity and stability at high temperatures and are suitable for high-temperature measurements; while other thermocouples (such as E-type and T-type) have better performance at low temperatures. Excellent linearity and accuracy, suitable for low temperature measurements.

Nonlinearity and Calibration:
The electromotive force-temperature characteristic curves of thermocouples with different graduation numbers may have different degrees of nonlinearity. Therefore, in practical applications, it may be necessary to calibrate the thermocouple with a specific graduation number to ensure the accuracy of the measurement results. This calibration typically involves measuring the electromotive force output over a range of known temperatures and using these data to build a calibration curve or lookup table.

Stability and durability:
Thermocouples with different graduation numbers in thermocouple sensors also have different stability and durability in long-term use. For example, R-type and S-type thermocouples generally have better oxidation resistance and corrosion resistance due to the use of precious metal materials, so they are more suitable for use in harsh environments.

Environmental adaptability:
Thermocouples with different graduation numbers also have different adaptability to the environment. For example, certain thermocouples may be more resistant to corrosion or high-temperature oxidation and therefore perform better in a specific industrial environment. Industrial assembly thermocouples are used as temperature measurement sensors. When used in conjunction with display instruments, recording instruments, electronic regulators, etc., they can cover a wide temperature range (-200°C to 1600°C) and are suitable for various media (liquid, steam , gases and solids) surface temperature measurement. The N, K, E, J, T, S, R, and B industrial thermocouple indexing numbers produced by the company not only comply with the International Electrotechnical Commission (IEC) standards, but also have reliable performance, long life, and unified design, so they are widely used in Petroleum, chemical, metallurgy, machinery and other industrial sectors.