In 1821 Thomas Seeback discovered that if a circuit is formed using two dissimilar metal conductors with one junction at a higher temperature than the other then a difference in temperature creates a small current (EMF) within the circuit. The resultant EMF (Electro Motive Force) is proportional to the temperature difference between the junction and is measured in millivolt.

There are several different recognized thermocouple types available. Each type has different temperature ranges as well as different recommended applications. For connecting the thermocouples to the temperature indicators Extension and Compensating cables are used.


Extension Cables are manufactured from conductors having the same nominal composition as well as the same emf output as those of the corresponding thermocouple. Letter ‘X’ following the designation of the thermocouple, e.g. KX, denotes these cables.


Compensating Cables are manufactured from conductors having different composition from the corresponding thermocouple but have similar emf output over a limited temperature range (generally 200°C). Letter ‘C’ following the designation of the thermocouple, e.g. ‘KC’, denotes these cables.

We manufacture RTD, Thermocouple Extension and Compensating cables with the PTFE (Teflon®) and Fibre Glass Insulation. We make following constructions commonly with parallel as well as twisted form.

1. PTFE/ PTFE
2. PTFE/ PTFE/ SS Braided
3. PTFE/ (SPC/ NPC/ BC) Braided/ PTFE
4. PTFE/ PTFE/ Fibre Glass
5. Fibre Glass/ Fibre Glass
6. Fibre Glass/ Fibre Glass/ SS
7. Fibre Glass/ Fibre Glass/ PTFE

We manufacture the above Insulated cables as per the requirement or specifications of the customer with insulating material PTFE and Fibre Glass.

We manufacture 2 Core, 3 Core, 4 Core and 6 Core RTD cables with above mentioned constructions using best quality Bare Copper, Silver Plated Copper and Nickel Plated Copper Conductors.

Thermocouple Extension and Compensating Cable Type	Conductor combinations		Approx. working Temp. (°C) range of measuring junction (Not related to wire size and Insulating Material)		NOTES
	+ Leg	- Leg	Continuous	Short Period
KX	Nickel-Chromium (Ni-Cr) Also Known as ‘Chromel®’	Nickel-Aluminium (Ni-Al) Also Known as ‘Alumel®’	0 to 1100	-180 to 1350	Most commonly used in oxidizing atmosphere
KC	Copper (Cu)	Copper-Nickel (Cu-Ni) Also Known as ‘Constantan’	--	--	Most commonly used in oxidizing atmosphere
EX	Nickel-Chromium (Ni-Cr) Also Known as ‘Chromel®’	Copper-Nickel (Cu-Ni) Also Known as ‘Constantan’	0 to 800	-40 to 900	Suitable for use in a vacuum or mildly oxidizing atmosphere
JX	Iron (Fe)	Copper-Nickel (Cu-Ni) Also Known as ‘Constantan’	+20 to 700	-180 to 750	Mostly used in plastics moulding industries. Iron oxidizes at low and at high temperature
TX	Copper (Cu)	Copper-Nickel (Cu-Ni) Also Known as ‘Constantan’	-185 to 300	-250 to 400	Excellent for low termperature and good for when moisture may be present.