Principle of Working Thermocouple

A Thermocouple is a sensor used to measure temperature. Thermocouples consist of two wire legs made from different metals. The wires legs are welded together at one end, creating a junction. This junction is where the temperature is measured. When the junction experiences a change in temperature, a voltage is created.  The voltage can then be interpreted using thermocouple reference tables to calculate the temperature.wp image thermocouple The working principle of thermocouple is based on three effects, discovered by Seebeck.

    • Seebeck effect
    • Peltier effect
    • Thomson effect

Type of Junctions

  • GROUNDED JUNCTION
  • UN GROUNDED JUNCTION
  • EXPOSED JUNCTION
  • ISOLATED JUNCTION

Types of Thermocouple with Its Accuracy

Thermocouple Types
Type Composition Accuracy Temperature range
B (+) Platinum – 30% Rhodium +/- 0.5% +250 to +1820 °C
(–) Platinum – 6% Rhodium
E (+) Chromel (Ni-Cr) +/- 1.7C or +/- 0.5% –270 to +1000 °C
(–) Constantan (Cu-Ni)
J (+) Iron +/- 2.2C or +/- .75% –210 to +1200 °C
(–) Constantan (Cu-Ni)
K (+) Chromel (Ni-Cr) +/- 2.2C or +/- .75% –250 to +1250 °C
(–) Alumel (Ni-Al)
N (+) Nicrosil (Ni-Cr-Si) +/- 2.2C or +/- .75% –250 to +1300 °C
(–) Nisil (Ni-Si-Mg)
R (+) Platinum +/- 1.5C or +/- .25% –50 to +1768 °C
(–) Platinum – 13% Rhodium
S (+) Platinum +/- 1.5C or +/- .25% –50 to +1768 °C
(–) Platinum – 10% Rhodium
T (+) Copper +/- 1.0C or +/- .75% –250 to +400 °C
(–) Constantan (Cu-Ni)

Type of Probes

General Purpose
Straight Type
Washer Type
L Type/ L Shape Thermovouple
Bayonet Cap Type
Straight Bayonet
L Shape Bayonet
Adjustable Bayonet Type
Washer Type/Ring Type
Threaded Type
Connection Head Type
Ferrul Fitting Type
Pin Type
Mineral Insulated Thermocouple(MI Type)
Leaf Type

Ordering Info

Type of Thermocouple
Sensor Dimension (Diameter and Length of Sensing Tip)
Lead Length(Cable Length)
Simplex/Duplex/MI Type (Mineral Insulated)
Cable Type (TEFLON/SS Braided)
Connecting Head Required(Casting Head)
Bayonet Cap Type
Any Fitting Required (1/4” , 1/2”, 3/4” , 1” Nipple/Ferrul Fitting)
Calibration Report

 

We also develop customized sensors for specific requirements.

Some of our Thermocouple Sample