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Thermocouple & RTD Cables
In 1821 Thomas Seebeck 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 the above Insulated cables as per the requirement or specifications of the customer with insulating material PTFE and Fibre Glass.
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Thermocouple
Extension and
Compensating
Cable Type
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Conductor combinations
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Approx. working Temp. (°C) range of measuring junction
(Not related to wire size and Insulating
Material)
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NOTES
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+ Leg
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-Leg
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Continuous
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Short Period
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KX
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Nickel-Chromium
(Ni-Cr)
Also Known as ‘Chromel®’
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Nickel-Aluminium
(Ni-Al)
Also Known as
‘Alumel®’
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0 to 1100
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-180 to 1350
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Most commonly used in oxidizing atmosphere
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KC
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Copper
(Cu)
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Copper-Nickel
(Cu-Ni)
Also Known as
‘Constantan’
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--
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--
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Compensating cable of Type K and should only be used when ambient temperature of the interconnection point between the cable and its Type K sensor is below 100°C
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KC
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Nickel-Chromium
(Ni-Cr)
Also Known as ‘Chromel®’
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Copper-Nickel
(Cu-Ni)
Also Known as
‘Constantan’
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0 to 800
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-40 to 900
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Suitable for use in a vacuum or mildly oxidizing atmosphere
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JX
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Iron
(Fe)
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Copper-Nickel
(Cu-Ni)
Also Known as
‘Constantan’
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+20 to 700
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-180 to 750
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Mostly used in plastics moulding industries.
Iron oxidizes at low and at high temperature
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TX
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Copper
(Cu)
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Copper-Nickel
(Cu-Ni)
Also Known as
‘Constantan’
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-185 to 300
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-250 to 400
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Excellent for low temperature and good for when moisture may be present.
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