Emerson Rosemount Volume 1, Quick Start Manual, Page: 16 / 32

Figure 7-1: Comparison of Thermocouples
32 1000 2000
Degrees Farenheit
0
20
40
60
80
M
il
li
v
o
lt
s
(a
p
p
ro
x
.)
Type E
Type J
Type T
Type K
Type K
Thermocouple Conditions for use
Type J Iron/
Constantan Maximum operating temperature of 760 °C (1400 °F). Used
with or without protective tubing where deficiency of free
oxygen exists. Protective tube not essential, but desirable for
cleanliness and longer service.
Type K Chromel/
Alumel Suitable for extended use in temperatures reaching 1150 °C
(2102 °F). Use of metal or ceramic protective tube desirable,
especially in reducing atmospheres. In oxidizing atmospheres,
protective tubing necessary only to promote cleanliness and
longer service.
Type E Chromel/
Constantan Suitable for use at temperature up to 871 °C (1600 °F) in
vacuum or inert, mildly oxidizing, or reducing atmosphere.
Not subject to corrosion at cryogenic temperatures. Has
highest EMF output per degree of all commonly used
thermocouples.
Type T Copper/
Constantan Operating temperature range of –180 to 371 °C (–292 to 700
°F). Use in either oxidizing or reducing atmospheres.
Protective tubing necessary only to promote cleanliness and
longer service. Stable at lower temperature. Superior for a
wide variety of uses in cryogenic temperatures.
Table 7-1: Characteristics of Series 183 Thermocouple Types
ISA
thermocouple
types Thermocouple
wire alloys Temperature
range
Limits of error
(interchangeability)
°C °F
J Iron/
Constantan 0 to
760 32 to
1400 ±1.1 °C (2.0 °F) or ±0.4% of
measured temperature,
whichever is greater
Quick Start Guide March 2021
16 Emerson.com/Rosemount