Thermocouple types and probes and thermocouple cables used for measurement of temperature, mode of furnace thermocouple working and high-temperature thermocouples working procedure, the functioning of the thermistor. Calibration of temperature sensors, the material of construction of various thermocouple based on the utilisation, mechanism of fitting the thermocouple to the process equipment and working principle of thermocouple testing. B,E,J,K,R,S,T types of thermocouple comparison
Sr no
|
Type
|
Positive wire
|
Negative wire
|
Temperature range 0C
|
Linearity
|
1
|
B
|
Pt-70—Rh-30
|
Pt-94—Rh-6
|
0 to 1860
|
Good at high temperature
|
2
|
E
|
Chromel
|
Constantan
|
-196 to 999
|
Good
|
3
|
J
|
Iron
|
Constantan
|
-196 to 760
|
Nearly linear between 149 to 438
|
4
|
K
|
Chromel
|
Alumel
|
-190 to 1371
|
Most linear
|
5
|
R
|
Pt-87—Rh-13
|
Platinum
|
-18 to 1704
|
Good at high temperature
|
6
|
S
|
Pt-90—Rh-10
|
Platinum
|
-18 to 1760
|
Good at high temperature
|
7
|
T
|
Copper
|
Constantan
|
-190 to 399
|
Same as J
|
8
|
Tungsten W
|
W 74 –Re 26
|
-18 to 2316
|
Good at high temperature
| |
9
|
W 94 –Re 6
|
W 74 –Re 26
|
-18 to 2316
|
Good at high temperature
| |
10
|
Copper
|
Gold – Cobalt
|
-268 to -18
|
Linear above 60k
| |
11
|
Ir 40- Rh 60
|
Ir
|
-18 to 2093
|
Good at high temperature
|
Pt- Platinum
Rh- Rhodium
W- Tungsten
Re- Rhenium
Ir-Iridium
Sr no
|
Type
|
Positive wire
|
Negative wire
|
Suitable atmosphere
|
1
|
B
|
Pt-70—Rh-30
|
Pt-94—Rh-6
|
Inert or slow oxidizing
|
2
|
E
|
Chromel
|
Constantan
|
Oxidizing
|
3
|
J
|
Iron
|
Constantan
|
Reducing
|
4
|
K
|
Chromel
|
Alumel
|
Oxidizing
|
5
|
R
|
Pt-87—Rh-13
|
Platinum
|
Oxidizing (fast response)
|
6
|
S
|
Pt-90—Rh-10
|
Platinum
|
Oxidizing
|
7
|
T
|
Copper
|
Constantan
|
Oxidizing or reducing(good corrosion resistance)
|
8
|
Y
|
Iron
|
Constantan
|
Reducing
|
9
|
--
|
Tungsten W
|
W 74 –Re 26
|
Inert or vacuum(high temperature)
|