Application principle: There is a certain residual gas in the high vacuum environment using the oil diffusion pump. More than 80% are steam, oil vapor and other high boiling steam, but its ability to remove residual gas is low and the time is long. Moreover, all residual gases are also sources of contamination of the workpiece, which affects the yield and quality of the product. Cryogenic pumps are a good choice for solving such problems. The working principle of the cryogenic pump: a refrigeration coil that can reach below -120 °C, placed in the vacuum chamber or the pump port of the oil diffusion pump, through the surface of the low-temperature condensation effect, quickly capture the residual gas of the vacuum system. This greatly shortens the vacuuming time (60-90% of the pumping time can be shortened) and a clean vacuum environment (the vacuum can be increased by half an order of magnitude to 10-8 Torr, 10-5 Pa). In practical applications, they can be divided into two categories depending on where they are placed: 1. Water vapor trap: Its refrigeration coil is often installed between the high valve and the vacuum chamber or in the vacuum chamber, and the upper and lower chambers of the winding coating. It is suitable for applications where the coating material such as plastic low-temperature coating and winding coating has a large amount of gas release. The coil needs to have a heating defrosting device to return the coil to normal temperature before opening the door, to prevent the low temperature coil from absorbing a large amount of water vapor from the atmosphere and frosting, which affects the next vacuum. 2, low temperature cold trap: placed in the pump port of the oil diffusion pump, below the high valve, its main function is to prevent the oil diffusion pump return oil, but also can speed up the pumping speed and increase the vacuum. Since the system is in a vacuum, no defrost is required. According to the needs, the two can be installed separately or at the same time. The company's R & D and production -135 ° C deep cold water vapor trap pump, using a single compressor, automatic cascade refrigeration, imported compressors and refrigeration accessories, environmentally friendly hybrid Refrigerant production, replacing liquid nitrogen, saves costs. It has the characteristics of fast cooling speed, high efficiency, low temperature and convenient maintenance. Its performance index is in a leading position in China, reaching or exceeding the international advanced level. Main performance characteristics 1. Rapid adsorption of water and oil vapor can shorten the exhaust time by 60-90%; 2, rapid cooling, cooling to -120 ° C within 3 minutes, the lowest can be -150 ° C; 3, 2 minutes hot air defrosting, quickly return to temperature, 5 minutes can be cooled again; 4, one device can design two-way load output; 5. Imported compressors, environmentally friendly mixed refrigerants; 6, touch screen + PLC = perfect automation control; 7, with two-way load inlet and outlet temperature display, local temperature display; 8. When the standby temperature arrives, there is an indicator light to start cooling. 9. Defrost temperature is freely set; 10. It has water temperature and exhaust temperature display; 11. Low water and high water temperature alarm; 12, the compressor exhaust is too high, the pressure is too high protection; 13, power off, lack of phase alarm; 14. Local and remote control can be freely converted; 15. RS485 computer data interface, the computer can read temperature data and control. Both IgM and IgG are immunoglobulin which are produced by the immune system to provide protectionagainst the 2019-nCoV. Some patients with negative results in nucleic acid test show positive in IgM test,indicating that the IgG / IgM detection is one of the effective methods for the diagnosis of 2019-nCoV. Office Testing Kit NINGBO AUTRENDS INTERNATIONAL TRADE CO., LTD , https://www.metests.com