By visiting this site, you accept the use of cookies. More about our cookie policy.

Thermocouple operating principle

Technical Characteristics

To understand how a thermocouple works, it is not necessary to know the Seebeck effect in detail. It is sufficient to understand that the device consists of two elements with a zero potential difference, which changes depending on the thermal effect on the element. A variety of thermocouples represent both nickel-based alloys and compounds such as:

-platinum-rhodium-platinum;

-tungsten-rhenium;

-tungsten-rhenium; -tungsten-molybdenum.

Thermocouple operating principle

The principle of operation is based on the thermoelectric effect, when heated there is a potential difference between conductors of different materials. For more accurate readings when heating is insignificant, thermocouples with high thermoelectric force are used. They have positive electrodes: copper or chromel or iron, and negative electrodes: alumel or copel or constantan. Among copel thermocouples, the thermocouple with a chromel electrode (TCK) occupies the first place for thermal emf value, which is used at temperatures up to 800 °C, the second place - with a copper electrode, after descending: - with an iron electrode (up to 760 °C). Compensation wires carry out potential transfer to the recording sensor. For such wires, cheaper wires are used: from constantan, chromel of K or KM grade, copel, etc. Copel and constantan are used in electric measuring instruments for production of resistance standards.

Types of thermocouples and measuring ranges

t° 200 - 1000 °C - alumel - chromel (TXA);

t° 200 to 800 °C - copel - chromel (TXA);

t° -40 to 900 °C - constantan - chromel (TXA);

t° up to 300 °C - copper - constantan;

t° from 0 to 760 °C - iron-copper;

t° in an inert medium up to 3000 °C - tungsten-rhenium.

measures ultra-low cryogenic temperatures - iron-constantan thermocouple;

Percent alumel composition

Fe Co Mn Impurities C Mn Al Ni+Co Si
≤ 0.3 0.6 - 1.2 1.8 - 2.7 ≤ 0.7 ≤ 0.1 1.8 - 2.7 1.6 - 2.4 91.5 - 95.15 0.85 - 1.5

Percentage chromel composition

Ni+Co Fe C Co Si Mn Si Impurities Al
87.4 - 90.4 ≤ 0.3 ≤ 0.2 9 - 10 ≤ 0.4 ≤ 0.3 ≤ 0.4 ≤ 1.4 0.6 - 1.2

Percentage composition of the copel

C Fe Ni+Co Si Impurities Cu Mn
≤ 0.1 ≤ 0.15 42.5 - 44 ≤ 0.1 ≤ 0.6 54.4 - 57.4 0.1 - 1

Supplier

Where can I find out how a thermocouple works? Supplier "Auremo" offers to buy a thermocouple today on favorable terms. Large selection in stock. Conformity to GOST and international quality standards, the price is optimal from the supplier. Buy thermocouple today. Wholesale customers price - favorable.

Buy at a reasonable price

Auremo" company offers to buy thermocouple on favorable terms. In stock the widest selection. Always in stock thermocouples, price - due to technological features of production without the inclusion of additional costs. The quality corresponds to GOST and international standards. Optimal price from the supplier. Buy thermocouple today. We are waiting for your orders.

Our consultant will save your time

+49 (170) 650 7006
E-mail:
Telegram:
WhatsApp:

Subscription

Special offers and discounts. :)