Difference between Extension, Compensating & Thermocouple Conductors

The thermocouple conductors are used to manufacture thermocouple sensors to sense the temperature directly; however extension & compensating conductors are used in extension/compensating cables that used to extend the thermocouple mV signal from thermocouple sensors to panel. Extension & compensating grade conductors have typically lower temperature limit & accuracy as compared to Thermocouple grade conductors.

Major differences among three types of conductors are as follow

Thermocouple Conductors

• These are called original conductors used to make thermocouple sensor.
• It has special limits of accuracy (Class 1)as per IEC 60584.3 that is 1 . 5 °C or 0 . 4 % of temperature.
• Temperature ranges of these conductors are maximum measuring range of thermocouple type.
• Costly as compared to Extensions & Compensating conductors.
• In flexible thermocouple wire & cables these conductor are used.

Extension Conductors

• Extension grades conductors have same conductor material as of thermocouple one but with lower accuracy.
• It has standard limits of accuracy (Class 2)as per IEC 60584.3 that is 2.5 °C up to 200 °C
• Temperature ranges of these conductors are maximum up to 200 °C
• Costly as compared to compensating but cheaper than thermocouple grades conductors.
• These conductors are used to make wires & cables, same cables are used to extend the thermocouple output mV signal to panel.
• Extension conductors not available with R/S/B type thermocouple

Compensating Conductors

• Compensating grades conductors are copper based material having similar
• characteristicsas of thermocouple over a very limited temperature range.
• It has standard limits of accuracy (Class 2)as per IEC 60584.3 that is 2.5 °C up to 100 °C only
• Temperature ranges of these conductors are up to 100 °C only.
• Cheapest among all
• hese conductors are used to make wires & cables, same cables are used to extend the thermocouple output mV signal to panel.
• Maxallowed Cable temperature range is up to 100 °C.
• Available in KCB & KCA (Ktype) RCA ® type), SCA (Stype ) , BC ( BType) thermocouple compensating conductors