International Colour coding for Thermocouple Wire Insulation ~ Learning Instrumentation And Control Engineering Learning Instrumentation And Control Engineering

International Colour coding for Thermocouple Wire Insulation

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Thermocouple (T/C) lead wires consist of two individual wires (positive and negative), enclosed by coloured insulation sheath:
Thermocouple Wire Insulation Colour Coding
Due to the Seebeck effect, thermocouple wires have a set polarity such that positive and negative wires must be connected to the correct terminals. A variety of standards exist for lead wire insulation colours to identify each thermocouple type.The different standards utilize unique wire colours to differentiate
between the positive and negative leads. 
In North America it is typical that the negative lead is red in accordance with   ASTM E230. However, the most widely used global standard for thermocouple wires is IEC 60584 where the negative lead is typically white.

When applying thermocouples, the standard to which the device is manufactured must be known so that the correct colour code is followed. There are other standards used in various countries: BS1843 - United Kingdom and Czech Republic); DIN43710 -  (Germany), JIS-C1610 (Japan);NFC 42-324 -  (France)
The varrious colour codes and international standards as applied to thermocouple wire insulation colour coding is tabulated below:
T/C type
North America ASTM E230
International IEC 60584
BS 1843
(UK)
DIN 43710
(Germany)
JIS C1610
(Japan)
NFC 
42-324
(France)
Thermocouple Grade
Extension Grade
B
Negative Conductor
N/A
Red
White 
N/A
Grey
Grey
N/A
Positive Conductor
N/A
Grey
Grey 
N/A
Red
Red
N/A
Sheath
N/A
Grey
Grey
N/A
Grey
Grey
N/A
E
Negative Conductor
Red
Red
White
Blue
Black
White
Purple
Positive Conductor
Purple
Purple
Purple
Brown
Red
Red
Yellow
Sheath
Brown
Purple
Purple
Brown
Black
Purple
Purple
J
Negative Conductor
Red
Red
White
Blue
Blue
White
Black
Positive Conductor
White
White
Black
Yellow
Red
Red
Yellow
Sheath
Brown
Black
Black
Black
Blue
Yellow
Black
K
Negative Conductor
Red
Red
White
Blue
Green
White
Purple
Positive Conductor
Yellow
Yellow
Green
Brown
Red
Red
Yellow
Sheath
Brown
Yellow
Green
Red
Green
Blue
Yellow
N
Negative Conductor
Red
Red 
White
Blue 
N/A
N/A
N/A
Positive Conductor
Orange
Orange
Pink
Orange
N/A
N/A
N/A
Sheath
Brown
Orange
Pink
Orange
N/A
N/A
N/A
R
Negative Conductor
N/A
Red
White
Blue
White
White
Green
Positive Conductor
N/A
Black
Orange
White
Red
Red
Yellow
Sheath
N/A
Green
Orange
Green
White
Black
Green
S
Negative Conductor
N/A
Red
White
Blue
White
White 
Green
Positive Conductor
N/A
Black
Orange
White
Red
Red
Yellow
Sheath
N/A
Green
Orange
Green
White
Black
Green
T
Negative Conductor
Red
Red
White
Blue
Brown
White
Blue
Positive Conductor
Blue
Blue
Brown
White
Red
Red
Yellow
Sheath
Brown
Blue
Brown
Blue
Brown
Brown
Blue