When two dissimilar metal wires are joined at the ends and are kept at different temperature TR and TS, a continuous thermoelectric current flows owing to the Seebeck effect as shown in Fig. 5.31a. If the wires are cut, an open-circuit Seebeck voltage is measured which is proportional to the temperature difference.
If TR is constant, the Seeback voltage is proportional to Ts. The associated Peltier effect is the increase or decrease of the junction temperature when an external current flows in the thermocouple (TC) wires. Reference 77 gives a description of these effects and their interrelationships.
Figure 5.31 Thermocouples. (a) Seebeck effect. (b) Measurement setup for remote sensing. |
Figure 5.31b shows an arrangement when the measuring equipment is remote from the sensing TC. Matched extension TC wires are used and the reference junctions are formed at the measuring equipment. The reference junctions must be kept at a constant temperature, mostly at ambient room temperature TA.
This requirement can also be satisfied by electronically providing a reference voltage compensation.
Thermocouples used in industry are made from several combinations of metals.
Table summarizes the properties of TCs that are commonly used, and a complete set of thermocouple reference tables is given in Ref. 76. The basic measuring instrument used with these thermocouples is the potentiometer, but direct-reading, analog, and digital meters of many kinds are also available from manufacturers.
Thermo Couple Manufacturers
ReplyDeleteIndustries Dependent on Sensitive Thermo Couple
A thermocouple is a simple but highly effective temperature sensor that uses the joining of wires made from two different metals or alloys to produce a voltage measure and thereby determine the heat range that exists within a particular area.
China Thermocouple, China Thermocouple Manufacturers
K Type Thermocouple-K Type Thermocouple Manufacturers
Industrial Thermocouple Supplies Pty Ltd,
India's leading manufacturer of thermocouple tips
OMEGA Engineering, Inc. - Precision Manufacturing - OEM RTDs
Pakistan Thermocouple, Pakistan Thermocouple Manufacturers ...
J Type Thermocouple-J Type Thermocouple Manufacturers ...
Thermocouple Manufacturers in Ahmedabad - Grotal.com
Thermocouple Manufacturers in Kolkata - Justdial
for more details
please contact
http://www.frontierprocess.com/about.html
nice
ReplyDeleteGreat share thanks for writing this
ReplyDeleteThermistor vs Thermocouple