There are problems with the casing of domestically produced level measuring instruments

　　With the rapid development of my country's national economy and the acceleration of technological process, the level measurement instrument technology has achieved unprecedented development. Since the level measurement instrument can reduce the loss of materials, save energy efficiently, improve production efficiency and reduce safety accidents, the accurate level measurement instrument plays a pivotal role in industrial production. The level measurement instrument is one of the basic design contents of the industrial production system. Its design basis is to correctly select the level measurement instrument according to the requirements of industrial production and determine the reasonable control scheme to obtain a good level measurement system.

　　At present, the instruments used for level measurement mainly include: vibrating rod level switch, magnetic flap level meter, radio frequency admittance level switch, rotary paddle level switch, float level meter, tuning fork level meter, ultrasonic level meter and radar level meter. Most of their shells are made of aluminum alloy, and the quality of aluminum alloy directly affects the performance, quality and reliability of the instrument. Some small domestic companies are eager for quick success and choose public mold shells, which are cheap and the shell material is basically recycled aluminum. The use of such shells will undoubtedly seriously damage the reliability of the whole machine and affect the quality of the product. So, what quality problems do the shells of domestically produced level measurement instruments usually have?

　　First of all, during the die-casting process of recycled aluminum shells, there will be some fine granular objects on the surface to varying degrees. The presence of these fine particles causes some defects on the shell surface, which are difficult to find without careful observation or touching with your hands. These small defects will greatly affect the oxidation, electrophoretic painting and appearance of the appearance.

　　Secondly, the chemical composition of recycled aluminum is not up to standard, and there are generally problems such as high hardness and poor plasticity of the needle-like structure. In addition, the tensile strength of the manufacturing process of this material is very low, and not only yellow rust will appear on the surface of the shell, but also cracks and pores will appear. The quality of the instrument shell using this material is inevitably greatly compromised.

　　Finally, the thickness of the recycled aluminum oxide film is thin. The national standard stipulates that the thickness of the aluminum profile oxide film should not be less than 10um. The porosity of the coating after chemical nickel plating is extremely high. Due to the large reduction in the sealing time and the reduction in the loss of chemical reagents, although the cost is reduced, the corrosion resistance of the profile is also greatly reduced. During the storage and use of the product, once it comes into contact with the corrosive medium in the air, it will accelerate the corrosion of the base of the aluminum alloy shell, causing bubbling and shedding of the coating.