Thermocouple Types

Thermocouple Type Material Magnetic ASTM Color Coding IEC Color Coding
J Iron
Constantan
Yes
No
White
Red
White
Black
T Copper
Constantan
No
No
Blue
Red
White
Brown
K Chromel
Alumel
No
No
Yellow
Red
White
Green
E Chromel/Constantan No
No
Purple
Red
White
Violet
P Platinel N/A N/A N/A
S Platinum 10% Rhodium
Pure Platinum
No
No
Black
Red
White
Orange
R Platinum 13% Rhodium
Pure Platinum
No
No
Black
Red
white
Orange
B Platinum 30% Rhodium
Platinum 6% Rhodium
No
No
Grey
Red
White
Grey
N Nicrosil/Nisil No
Slightly
Orange
Red
White
Pink
C Tungsten 5% Rhenium/ Tungsten 26% Rhenium No
No
White
Red
N/A

RTD Standards

Organization Standard Alpha Nominal
Resistance(ohms)
At 0°C
American Scientific
Apparatus Makers
Association (SAMA)
RC21-4-1966 0.003923 98.129
British Standards
Association
b.S. 1904-1964 0.003850 100
Normenstelle
Elektrotechnik
DIN 43760 0.003850 100
International Electrotechnical
Commission (Supersedes
BS&DIN)
IEC 751: 1983 0.003850 100
US Department
of Defense
MIL-T-24388 0.00392 100
Material
Symbol
Sheath
Material
Melting
Point(°F)
Max Temp;
In Air(°F)
Atmosphere*
H 304 SS 2550 1650 ORNV
J 310 SS 2550 2100 ORNV
L 316L SS 2550 1650 ORNV
O 446 SS 2700 2100 ORNV
M Inconel 600 2500 2100 ONV
P Inconel 702 2620 1500 ONV
Q Platinum 3216 3000 ON
R Molybdenum 4750 1000 VNR
T Titanium 3300 600 V
V STABALOY 2552 2220 ORNV

*KEY

O=Oxidizing, R=Reducing, N=Neutral, V=Vacuum

Suggested Upper Limit for Outside Diameter (Single Element) °C (°F)
Sheath Thermocouple Type
In mm T J E K N
1/25" 1.0 260° (500°) 260° (500°) 300° (570°) 700° (1290°) 2700° (1290°)
1/16" 1.6 260° (500°) 440° (825°) 510° (950°) 920° (1690°) 920° (1690°)
1/8" 3.2 315° (600°) 520° (970°) 650° (1200°) 1070° (1950°) 1070° (1950°)
3/16" 4.8 370° (700°) 620° (1150°) 730° (1350°) 1150° (2100°) 1150° (2100°)
1/4" 6.3 370° (700°) 720° (1330°) 820° (1510°) 1150° (2100°) 1150° (2100°)
3/8" 9.5 370° (700°) 720° (1330°) 820° (1510°) 1150° (2100°) 1150° (2100°)

Cut Sheet

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