Introduction
These cables can also be termed as instrumentation cables as they are used for process temperature measurement. The construction is similar to paired instrumentation cable but the conductor material is different. Thermocouples are used in processes to sense temperature and is connected to the pyrometers for indication and control.
The thermocouple and pyrometers are electrically conducted by thermocouple extension/compensating cables. The conductors used for these cables are required to have similar thermo-electric (emf) properties as that of the thermocouple used for sensing the temperature. The cables are manufactured as per IS:8784, ANSI-MC 96. 1, B.S., ENI, DIN and customers’ specification.
Characteristics of Extension and Compensating Cables | Colour code for Thermocouple Extension and Compensating Cables | |||||
---|---|---|---|---|---|---|
British Standard BS 1843 | American Standard ANSI MC 96.1 / ASTM E230 | Indian Standard IS 8784 | International Electro Technical Commission IEC 60584-3 | |||
Code | Conductor Composition | Code | Code | Code | Code | |
+ VE Terminal | – VE Terminal | |||||
KX | Nickel Chromium | Nickel Aluminium | Brown (+) , Blue (-) , Red (Sheath) |
Yellow (+) , Red (-) , Yellow (Sheath) |
Red (+) , Green (-) , Green (Sheath) |
Green (+) , White (-) , Green (Sheath) |
JX | IRON | Copper-Nickel | Yellow (+) , Blue (-) , Black (Sheath) |
White (+) , Red (-) , Black (Sheath) |
Red (+) , Blue (-) , Blue (Sheath) |
Black (+) , White (-) , Black (Sheath) |
TX | Copper | Copper-Nickel | White (+) , Blue (-) , Blue (Sheath) |
Blue (+) , Red (-) , Blue (Sheath) |
Red (+) , Black (-) , Black (Sheath) |
Brown (+) , White (-) , Brown ( Sheath) |
EX | Nickel Chromium | Copper-Nickel | Brown (+) , Blue (-) , Brown (Sheath) |
Purple (+) , Red (-) , Purple (Sheath) |
Red (+) , Violet (-) , Violet (Sheath) |
Violet (+) , White(-) , Violet ( Sheath) |
RX /SX | Copper | Copper-Alloy | White (+) , Blue (-) , Green (Sheath) |
Black (+) , Red (-) , Green (Sheath) |
Red (+) , White (-) , White (Sheath) |
Black (+) , Red (-) , Green (Sheath) |