Thermocouples with a ceramic protection tube and a built-in wire element

Thermocouple assemblies with a ceramic protection tube (05-TKT) are mainly used for general temperature measurement in gaseous environments up to 1800°C.

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These thermocouples are mainly applied in gaseous media up to 1800 °C. A corrosive and abrasive environment is often created at these high temperatures. Protection tubes from high-quality, heat resistant, technical ceramics are perfect for these types of conditions. To prevent and postpone poisoning as much as possible, it is advisable to use high quality, gastight ceramics. It is also an option to put a provision in the sensor which makes calibration possible while the sensor is operational.

Technical specifications

Measurement and regulation processes can lead to strenuous operational demands through abrasion and corrosion. This is the reason for the protection tubes of these thermal sensors consisting of high grade heat-resistant ceramics. Metals often will not be able to bear the stress of this strain.

Aside from the industry customary oxide ceramics (purity of up to 99,8%), we offer non-oxide ceramics and individual solutions with a diversity of dimensions and materials. In most cases, GÜNTHER GmbH will have these items available from stock.

The assemblies of this product line can be fitted with an additional ceramic inner tube, which, in most cases, considerably increases endurance strength and total durability.

The maximum operating temperature is dependent both upon the mounting orientation (vertical / horizontal) and the corrosiveness of the respective ambient media.

Thermoelectric voltages and tolerances of our thermocouples are pursuant to DIN EN 60584, class 1.


Characteristics of the most usual ceramic types

  Unit porous
Type pursuant DIN / C530 C610 C799
Thermal Shock Resistance / Very Good

to Good

Impermeability / Porous Gas-Tight Gas-Tight
Maximum Constant Temperature °C 1650 1600 1850
Al2O3-Content % 73-75% 60 99,7
Volume Weight g*m3 2,35 2,5 3,8-3,93
3-Point Bending Strength MPa 35 120 300
C-Modul GPa 60 110 370

Maximum application temperatures for Platinum-Rhodium-Platinum thermoelectric pairs

Type Diameter Maximum
S 0,35 mm 1350°C
S 0,50 mm 1600°C
R 0,35 mm 1350°C
R 0,50 mm 1600°C
B 0,35 mm 1600°C
B 0,50 mm 1800°C

Application areas of these types of Thermocouples: