Tungsten-rhenium thermocouple is characterized by high melting point of hot electrode wire (3300℃), low vapor pressure, easy oxidation; Good chemical stability in non-oxidizing atmosphere. Electromotive force, high sensitivity, mainly or cheap. At present, the non-contact method is used to measure the temperature above 1600℃, but the error of this method is large, such as the contact rule can accurately measure the real temperature.
In high temperature thermocouple, precious metal thermocouple is expensive and z.uli high temperature can only be below 1800℃, and tungsten-rhenium thermocouple not only high temperature limit, but also good stability, therefore, tungsten-rhenium thermocouple in metallurgy, building materials, aerospace, aviation and nuclear energy and other industries have been widely used. Tungsten resources are abundant in China, tungsten-rhenium thermocouple is cheap, can partly replace precious metal thermocouple (platinum-rhodium thermocouple), it is a promising temperature measurement material in the field of high temperature testing. Its high service temperature can reach 2800℃, however, above 2300℃, data dispersion. Therefore, the use of temperature is good at about 2000℃. Tungsten-rhenium thermocouples are easily oxidized and are suitable for use in inert or dry hydrogen gas, or they can only be used by isolating them from oxygen with dense protective tubes. Cannot be used in the atmosphere containing carbon (such as in the atmosphere containing hydrocarbons, the temperature exceeds 1000℃ will be corroded). Tungsten or tungsten-rhenium tends to form stable carbides in a carbon-containing atmosphere, resulting in reduced sensitivity and brittle fracture, and accelerated carbonization in the presence of hydrogen. Tungsten-rhenium thermocouple oxidation resistance has been the focus of domestic and foreign scholars, and is committed to research and solution. The temperature range of the product is 0 ~ 1800℃, widely used in metallurgy, coking, chemical furnace, heat treatment, glass and other industries, it has the advantages of high precision, low price, stable performance, not limited by the atmosphere of the working environment, is the ideal product to replace the platinum rhodium thermocouple. 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, indexing number: W-RE3/25, W-RE5/26 2, temperature range: 0 ~ 1800℃ 3, temperature measurement accuracy: < ± 1% T; < ± 0.5%T 4, time constant: ≥180 s 5, insulation resistance: > 5M ω 6, Specifications and dimensions: 300,500,750,1000,1100 (mm) tungsten-rhenium rapid temperature measurement of molten steel thermocouple is specially designed for measuring molten steel, liquid iron and other metal melt temperature, it has the advantages of small volume, fast thermal response, high accuracy, low price. Its technical indicators are as follows: 1, z.uli high temperature measurement temperature: 1800℃ 2, temperature measurement accuracy :≤ 0.5% 3, insulation resistance :≥30 M ω 4, measurement rate :≥98% 5, reaction time: < 5 s At present my company production of tungsten and rhenium thermocouple is divided into three categories: one is the use of fine ceramic protection tube. The specifications of ceramic tube are: diameter ф 8, ф 10, ф 12, ф 14, ф 16, length 300~1100mm, this kind of thermocouple is not limited by the working environment atmosphere can be used in any atmosphere for a long time, the temperature range is 0~1800℃ another kind of pure molybdenum protection tube. Molybdenum tube and tungsten tube specifications: diameter of ф 6, ф 8, ф 10mm, length of 500~700mm, this thermocouple can only work in vacuum, reduction or inert gas protection environment for a long time, molybdenum tube z.i is best in 1800℃ under the temperature of long-term use, short-term use temperature can reach 2000℃; Another type is the tungsten protection tube. Tungsten tubes work at 2100℃ for a long time, but are difficult to process, making them very expensive.