The characteristics of tungsten-rhenium thermocouple are: the hot electrode wire has a high melting point (3300 ° C), a low vapor pressure, and is easily oxidized; it has good chemical stability in a non-oxidizing atmosphere. The electromotive force is large, the sensitivity is high, and the price is mainly low.

At present, the non-contact method is mostly used to measure the temperature above 1600 ℃, but the error of this method is large. For example, the real temperature can be accurately measured by the contact method. Among high-temperature thermocouples, precious metal thermocouples are expensive and the highest temperature can only be below 1800 °C, while tungsten-rhenium thermocouples not only have a high temperature measurement limit, but also have good stability. Therefore, tungsten-rhenium thermocouples are used in metallurgy, Building materials, aerospace, aviation and nuclear energy and other industries have been widely used. my country is rich in tungsten resources, and tungsten-rhenium thermocouples are cheap and can partially replace precious metal thermocouples (platinum-rhodium thermocouples). It is a promising temperature measurement material in the field of high-temperature testing. Its z.ui high operating temperature can reach 2800 ℃, however, when it is higher than 2300 ℃, the data is scattered. Therefore, the best use temperature is around 2000°C.

Tungsten-rhenium thermocouples are easy to be oxidized and are suitable for use in inert or dry hydrogen, or they can be used only when they are isolated from oxygen with a dense protective tube. It cannot be used in carbon-containing atmosphere (for example, in an atmosphere containing hydrocarbons, it will be corroded when the temperature exceeds 1000 °C). Tungsten or tungsten-rhenium tends to form stable carbides in a carbon-containing atmosphere, which reduces its sensitivity and causes brittle fracture, and in the presence of hydrogen, accelerates carbonization.

The anti-oxidation problem of tungsten-rhenium thermocouple has always been a topic of concern to scholars at home and abroad, and is committed to research and solution. Assembly type high temperature and high pressure tungsten rhenium thermocouple, the temperature measurement range of this product is 0 ~ 1800 ℃, widely used in metallurgy, coking, chemical furnace, heat treatment, glass and other industries, it has high precision, low price, stable performance, no It is an ideal product to replace platinum-rhodium thermocouples due to the advantages of limited working environment and atmosphere. The tungsten-rhenium thermocouple produced by our company has been widely used in many units, and its performance has reached the level of similar foreign products. Its technical indicators are as follows:

1. Graduation number: W-Re3/25, W-Re5/26

2. Temperature measurement range: 0～1800℃

3. Temperature measurement accuracy: < ± 1% t; < ± 0.5% t

4. Time constant: ≥180 s

5. Insulation resistance: > 5MΩ

6. Size: 300, 500, 750, 1000, 1100 (mm)

Tungsten-rhenium molten steel rapid temperature measurement thermocouple is specially designed and manufactured for measuring the temperature of molten steel, molten iron and other metal melts. It has the advantages of small size, fast thermal response speed, high accuracy and low price. Its technical indicators are as follows:

1. z.ui high temperature measurement temperature: 1800℃

2. Temperature measurement accuracy: ≤ 0.5%

3. Insulation resistance: ≥30 MΩ

4. Measurement success rate: ≥98%

5. Response time: < 5 s

At present, the tungsten-rhenium thermocouples produced by our company are divided into three categories:

One is the fine ceramic protection tube used. The specifications of the ceramic tube are: diameter Ф8, Ф10, Ф12, Ф14, Ф16, length 300~1100mm, this type of thermocouple is not limited by the working environment atmosphere and can be used in any atmosphere for a long time. Use, the temperature measurement range is 0~1800 ℃

The other type is pure molybdenum protection tube. The specifications of molybdenum tube and tungsten tube are: diameter Ф6, Ф8, Ф10mm, length 500~700mm, this kind of thermocouple can only work in vacuum, reduction or inert gas protection environment for a long time, The molybdenum tube is best used at a temperature below 1800 °C for a long time, and the short-term use temperature can reach 2000 °C;

Another type is the tungsten protection tube. As for the tungsten tube, it can work at 2100 ℃ for a long time, but it is difficult to process, making it very expensive.