Partial pressure measurement standard for characterizing partial pressure analyzers and measuring outgassing rates

Abstract

In this work, a measurement standard was established for partial pressures in high and ultrahigh vacuum conditions. Three (or more, with higher uncertainty) different gases with known partial pressures from 10−8 to 10−2 Pa can be generated in a calibration chamber of an ultrahigh vacuum system by a continuous expansion method. The ratio between two partial pressures can range from 10−6 to 1. The readings of partial pressure analyzers can be calibrated by comparing them to known partial pressures. The calibration chamber is connected to a sample chamber, where outgassing samples can be inserted via a load lock. With an in situ calibrated partial pressure analyzer, the outgassing rate from the samples can be measured in a traceable way to the international systems of units.