Maintaining the degree of vacuum of reference room for capacitance manometer

Abstract

It is important to maintain the vacuum of the reference room for capacitance manometer for a long period of time. To perform this task, it is necessary to understand the exhaust capacity of the Non-evaporable getter in the reference room and to inspect whether the small amounts of leakage after forming the reference room are within an acceptable range. In this study, we performed the evaluations to ascertain the Non-evaporable getter capacity and estimate the lifetime. In addition, it is expected that the leak detection method using Kr gas is applicable to the leak detection of a very small amount of leakage after the formation of the reference vacuum room.