Thermocouple compensation wire
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I just read a post discussing the accuracy of thermocouple temperature measurement. It mentioned the issue of compensation wires. The thermocouples and wires we use are provided by the manufacturer. A question suddenly occurred to me. On what basis are the thermocouple compensation wires selected? Are there any certain rules? Thank you!
The compensation wire is selected according to the type of thermocouple used. Thermocouples with different graduations have corresponding compensation wires available. The compensation wire seems to be divided into two types: extension type and compensation type. The materials seem to be different. I don’t know what the difference is! Compensation wire model is equipped with a thermocouple. Thermocouple index number. Compensation wire alloy wire insulation layer colored positive and negative poles. Positive and negative SC. Platinum-rhodium 10-platinum thermocouple S SPC (copper) SNC (copper-nickel) red and green RC. Platinum-rhodium 13-platinum thermocouple R RPC (copper) RNC (copper-nickel) red and green KCA. Nickel-chromium-nickel silicon thermocouple K KPCA (copper) KNCA (constantan) Red and blue KCB KPCB (iron) KNCB (copper-nickel) Red and blue KX KPX (nickel-chromium) KNX (nickel-silicon) Red-black NC Nickel-chromium silicon-nickel silicon thermocouple N NPC (iron) NNC (copper-nickel) Red and gray NX NPX (nickel-chromium silicon) NNX (nickel-silicon) Red and gray EX Nickel-chromium-copper-nickel thermocouple E EPX (nickel-chromium) ENX (copper-nickel) Red brown JX Iron-copper-nickel thermocouple J JPX (iron) JNX (copper-nickel) red and purple TX Copper-copper-nickel thermocouple T TPX (copper) TNX (copper-nickel) red and white
Continuing from above, the extended type means that the two wires are made of the same material as the positive and negative electrodes of the thermocouple, such as KX KPX (nickel chromium) KNX (nickel silicon). The red and black compensation type means that the two wires are made of different materials from the positive and negative electrodes of the thermocouple. However, in a normal temperature environment (generally 0-100 degrees), the potential generated by the temperature difference is similar to that of the thermocouple, such as KC copper, copper, nickel, red and blue. In theory, The accuracy of the extended type should be better than the compensated type.
Thank you~~:lol :lol
Of course there is, first look at what kind of thermocouple to choose, and then select the cable based on the thermocouple.
The selection mainly depends on the model of the thermocouple.
KC type is greatly affected by temperature changes, KX type is less affected