Device and method for measuring built-in low-temperature pumping speed

Abstract

The invention provides a measurement device used for measuring a large built-in low-temperature pumping speed, firstly provides an unconcentrated flow device (16) of a dual-layer cylindrical structurethat effectively reduces the effects of the gas jet effect on the large built-in low-temperature pumping speed, firstly applies a method (matching a pressure reducer (23) with a sonic nozzle (22) toprecisely adjust the volume flow) to the field of the built-in low-temperature pumping speed measurement, provides a sonic nozzle-type gas supply device and provides a method for measuring the sonic nozzle-type large built-in low-temperature pumping speed by aiming at the gas supply mode.

Description

Built-in low temperature pump pumping speed measurement device and method 【Technical field】 The invention relates to a pumping speed measuring device of a built-in cryogenic pump, which belongs to the field of pumping speed measurement. 【Background technique】 The vacuum obtaining system is an effective device for obtaining a vacuum environment in a limited space (vacuum container). For a vacuum environment of less than 10-4Pa, traditional mechanical pumps, Roots pumps or pump sets have been difficult to achieve. To solve this problem, a cryopump based on the principle of condensation adsorption has emerged. The cryopump uses a low-temperature cold plate to adsorb gas molecules whose condensation temperature is higher than that of the cold plate. The larger the area of ​​the cold plate, the stronger the pumping capacity; the lower the temperature of the cold plate, the more types of gas molecules that can be extracted. Most of the early cryopumps were external, with a smal...

AI Technical Summary

Problems solved by technology

The disadvantage of the above two methods is that the air supply method is outdated, and it is necessary to manually adjust the needle valve and measure the number of oil dipsticks to convert the air supply volume; the diffuser fails to solve the jet effect of the introduced gas well, and does not eliminate the direction of the airflow Influence of characteristics on pumping speed measurement of built-in cryopump

Images