THERMOCOUPLE : TYPES, CONSTRUCTION, DETAILS
THERMOCOUPLE TYPES AND DETAILS :
Basically their are four types of Thermocouples according to the construction metals.
(i) Base Metal Thermocouple
(ii) Nobel Metal Thermocouple
(iii) Refractory Metal Thermocouple
(i) Base Metal T/C
Sr.
no
|
Type
|
Conductor Metals
|
Color code
|
Range
|
EMF range(mV)
|
Sensitivity
|
1
|
T
|
Cu(+ve) – Constantan(-ve)
|
Blue- +
Red- -
|
-270°C – 400°C
|
-6.258 – 20.869
|
40.5
|
2
|
J
|
Fe(+ve) –Constantan(-ve)
|
White- +
Red- -
|
-210°C-1200°C
|
-8.046 - 69.536
|
52.6
|
3
|
K
|
Chromel(+ve) –Alumel(-ve)
|
Yellow- +
Red- -
|
-270° C-1370°C
|
-6.458 – 54.807
|
38.8
|
4
|
E
|
Chromel(+ve) –Constantan(-ve)
|
Purple- +
Red- -
|
-270°C-1000°C
|
-9.835 - 76.358
|
67.9
|
5
|
N
|
Nicrosil(+ve) –Nisil(-ve)
|
Orange- +
Red- -
|
-270°C - 1300°C
|
-4.345 – 47.502
|
39
|
(ii) Nobel Metal T/C
Sr.
no
|
Type
|
Conductor Metals
|
Color code
|
Range
|
EMF range (mV)
|
Sensitivity
|
1
|
S
|
[Pt(90%)+Rhodium(10%)] –Pt(-ve)
|
Black- +
Red- -
|
-50℃ - 1760℃
|
-0.236 - 18.612
|
10.6
|
2
|
R
|
[Pt(87%)+Rhodium(13%)]
(+ve) –[Pt(94%)+Rhodium(6%)](-ve)
|
Black- +
Red- -
|
-50℃ - 1700℃
|
-0.026 – 21.006
|
12
|
3
|
B
|
[Tungsten(94%)+Rhodium(6%)]
(+ve) –[Tungsten(74%)+Rhodium(26%)]
(-ve)
|
Grey- +
Red- -
|
0℃ - 1820℃
|
0 – 13.814
|
7.6
|
Sr.
no
|
Type
|
Conductor Metals
|
Color
code
|
Range
|
EMF range
(mV)
|
Sensitivity
|
1
|
C
|
[Tungsten(94%)+Rhodium(6%)]
(+ve) –[Tungsten(74%)+Rhodium(26%)]
(-ve)
|
---
|
0℃ - 2400℃
|
---
|
---
|
2
|
G
|
Tungsten (+ve) –[Tungsten(74%)+Rhenium(26%)]
(-ve)
|
0℃ - 2400℃
|
|||
3
|
D
|
[Tungsten(97%)+Rhenium(3%)] (+ve)–[Tungsten(74%)+Rhenium(25%)]
(-ve)
|
0℃ - 2400℃
|
(iv) Special T/C
Sr.
no
|
Type
|
Conductor Metals
|
Color
code
|
Range
|
EMF range
(mV)
|
Sensitivity
|
1
|
---
|
[Indium(60%)+Rhodium(40%)]
(+ve) –Indium (-ve)
|
---
|
0℃ - 2000℃
|
||
2
|
---
|
Tungsten (+ve) –Molybdenum (-ve)
|
---
|
1250℃ – 2600℃
|
||
3
|
---
|
[Gold(50%)+Iron(50%)] (+ve) –Chromel (-ve)
|
---
|
-270℃ - 0℃
|
NOTE:
⏺ We can get the maximum sensitivity(67.9) from the E-type Base metal Thermocouple
⏺ [-270℃- 0℃] range is called Cryogenic range
Read Also....
BASIC DIGITAL LOGIC GATES: http://www.theincredibletruths.com/search/label/www.theincredibletruths.com%3EBasic%20Digital
Read Also....
BASIC DIGITAL LOGIC GATES: http://www.theincredibletruths.com/search/label/www.theincredibletruths.com%3EBasic%20Digital
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