High temperature thermocouple

Tungsten-rhenium-based wire (C) is used at temperatures up to 2000℃ and platinum-rhodium-based wire (B) is used at temperatures up to 1800℃ depending on the measured temperature and temperature of the thermocouple for high-temperature use (HT-THERMIC). Special wires such as Pt and 5% Mo-Pt・0.1%Mo, Ni・18%Mo-Ni can also be used for special environments such as nuclear power.

C (W•5%Re-W・26%Re) •Compatible atmosphere: Reduction, Inert, Vacuum, Nuclear Environment
Tungsten 5% Rhenium-Tungsten 26% Rhenium thermocouple wire was developed with the aim of preventing embrittlement by adding Rhenium to both legs and greatly improving mechanical strength. This thermocouple wire does not become embrittled even when heated to 1650℃, and can be annealed. This eliminates the issue of shifting in the early E.M.F and prevents wire breakage during use. As a result, it is becoming the mainstream of tungsten-rhenium thermocouples.
Thermoelectric power up to 0 to 900℃ has good linearity. This thermocouple has a good track record in use even in high-temperature nuclear environments.
Tungsten-rhenium alloys are easily oxidized and cannot be used in air or other oxidizing atmospheres.

B (Pt・30%Rh-Pt · 6%Rh) · Compatible atmosphere: oxidized, inert
A thermocouple using a Pt・Rh alloy containing Rh(30% in the (+) pole and a Pt・Rh alloy containing Rh (6%) in the (-)pole. Thermocouples are designed to increase the melting point and mechanical strength as the rhodium content of platinum increases, and to prevent degradation of the thermoelectromotive force due to the diffusion of (Rh) from the (+) pole to the(-)pole that occurs during the use of R and S thermocouples. In addition, it can be used continuously in oxidizing and neutral atmospheres, and even in a reducing atmosphere, it generally has a longer life than R thermocouples.
Using high-purity alumina (99.5% or more) material for the protective tube and insulation tube. Handle the thermocouple with care, and use alcohol or benzene to remove any dirt that may be contaminated by perspiration or oil.
Since rhodium in alloy components has a large neutron absorption cross section and is converted to palladium in a short period, it is not suitable for measuring nuclear environments.

Characteristics of thermocouple wire

Solid sintered insulation tubes are used for powder insulation materials such as magnesia and alumina at high temperatures of 1200℃ or higher because the insulation resistance drops rapidly. Generally, the insulation resistance of a solid insulation tube is about 10 times higher than that of a powder insulation of the same quality. HT-THERMIC mainly uses high-purity alumina and beryllia sintered insulated tubes to prevent wire breakage due to thermal stress.

Outline of characteristics of insulation tube

(NOTE)The maximum operating temperature represents the refractoriness of the insulator. To use as an insulation tube, it is necessary to consider the insulation resistance characteristics at the operating temperature. Please consult us when using the product near the maximum operating temperature.

It is well known that the most important point in determining thermocouple reliability and longevity is the proper selection of the protective tubing material. However, high temperature measurements in special environments where complex chemical reactions may occur between the thermocouple material and the thermocouple material require a high level of knowledge to select the material.

Outline of characteristics of protective tube material

(NOTE)V: Vacuum R: Reduction N: Inert O: Oxidative

Stability of Metals for High Temperature in Various Furnace Atmospheres

Stability of Metals for High Temperature in Various Furnace Atmospheres