热电极丝熔点高(3300℃)，蒸气压低，极易氧化；在非氧化性气氛中化学稳定性好。 Tungsten-rhenium thermocouple wire has high melting point (3300 ℃), low vapor pressure, and is easily oxidized. It has good chemical stability in a non-oxidizing atmosphere. Large electromotive force and high sensitivity, the main thing is cheap. Tungsten-rhenium thermocouples are extremely susceptible to oxidation and are suitable for use in inert or dry hydrogen, or they can be isolated from oxygen with a dense protective tube. Can not be used in carbon-containing atmosphere (such as in a hydrocarbon-containing atmosphere, the temperature exceeds 1000 ℃ will be corroded). Tungsten or tungsten thorium is easy to form stable carbides in a carbon-containing atmosphere, which reduces its sensitivity and causes brittle fracture. In the presence of hydrogen, it will accelerate carbonization. Tungsten-rhenium thermocouples are high temperature thermocouples. It has the advantages of good temperature-potential linear relationship, reliable thermal stability, and low price. With the display instrument, it can directly measure the temperature of liquid, steam and gas medium. It can partially replace platinum-rhodium thermocouples as high-tech metallurgical industry, high-temperature electronic thermoelectric system structural engineering and space transportation tools, and ultra-high temperature measurement tools for nuclear reactors. The relationship between the thermoelectric potential and temperature of the tungsten-rhenium thermocouple conforms to the ZBN05003-88 index table, which is equivalent to ASTME696-84 standard. It can be used in the range of 0 ~ 2300 ℃ under vacuum, reduction and inert atmosphere. Tungsten rhenium couplers with special protection tubes can also be used for a long time in an oxidizing atmosphere at 1600 ° C, and their price is lower than that of platinum-rhodium thermocouples.
从事化工行业的朋友应该不陌生吧，而你们了解钨铼热电偶的特点吗?不管大家了不了解，我在这里在做一个介绍，钨铼热电偶的特点是：热电极丝熔点高(3300℃)，蒸气压低，极易氧化;在非氧化性气氛中化学稳定性好。 Tungsten-rhenium thermocouples are no strangers to the chemical industry. Do you know the characteristics of tungsten-rhenium thermocouples? Regardless of everyone's understanding, I am here to introduce. The characteristics of tungsten-rhenium thermocouples are: High melting point (3300 ℃), low vapor pressure, easy oxidation; good chemical stability in non-oxidizing atmosphere. Large electromotive force and high sensitivity, the main thing is cheap. At present, when measuring temperatures above 1600 ° C, the non-contact method is often used. However, the error of this method is relatively large. If the contact method is used, the real temperature can be accurately measured. Among high-temperature thermocouples, high-temperature noble metal thermocouples (platinum-rhodium thermocouples) are expensive and the highest temperature can only be below 1800 ° C. Tungsten-rhenium thermocouples not only have a high temperature measurement limit, but also have good stability. Therefore, tungsten-rhenium thermocouples Even widely used in various industries. China has abundant tungsten resources. Tungsten-rhenium thermocouples are cheap and can partially replace high-temperature precious metal thermocouples (platinum-rhodium thermocouples). The maximum operating temperature of tungsten-rhenium thermocouples can reach 2800 ° C. However, when the temperature is higher than 2300 ° C, the data is scattered . Therefore, the best use temperature is around 2000 ° C. Tungsten-rhenium thermocouples are extremely susceptible to oxidation and are suitable for use in inert or dry hydrogen, or they can be isolated from oxygen with a dense protective tube. Can not be used in carbon-containing atmosphere (such as in a hydrocarbon-containing atmosphere, the temperature exceeds 1000 ℃ will be corroded). Tungsten or tungsten thorium is easy to form stable carbides in a carbon-containing atmosphere, which reduces its sensitivity and causes brittle fracture. In the presence of hydrogen, it will accelerate carbonization. The anti-oxidation problem of tungsten-rhenium thermocouples has always been a topic of concern to scholars at home and abroad, and is committed to research and solution. Our company has adopted the international advanced manufacturing process and successfully developed the assembled high temperature and high pressure tungsten rhenium thermocouple. The temperature range of this product is 0 ～ 1800 ℃, which is widely used in metallurgy, coking, chemical furnaces, heat treatment, glass, etc. Industry, it has the advantages of high accuracy, low price, stable performance, and is not restricted by the working environment atmosphere. It is an ideal product to replace platinum and rhodium thermocouples. The tungsten-rhenium thermocouple produced by our company has been widely used in many units, and its performance has reached the level of similar products at home and abroad.
Precautions during installation and use
在安装过程中需要特别注意，热电偶的安装插入孔必须安装定位保护套，对钼、钨、钽保护管制作的热电偶，安装过程中需特别小心，该保护管常温下硬而脆，很容易造成脆断。 1. Tungsten-rhenium thermocouples need special attention during the installation process. The installation insertion holes of the thermocouples must be installed with positioning protective sleeves. For thermocouples made of molybdenum, tungsten, and tantalum protection tubes, special care must be taken during the installation process. The protective tube is at room temperature. It is hard and brittle and can easily cause brittle fracture. 2. During the use of tungsten-rhenium thermocouples or during maintenance after use, if the thermocouples are not damaged, disassembly and assembly of tungsten-rhenium thermocouples is forbidden, and as far as possible, do not touch the hot end of the thermocouple. Later, the even wire became very brittle, so it was easy to cause the even wire to become brittle during the vibration process.