Practical guide to the use of Bayard–Alpert ionization gauges

Abstract

There are many potential problems in the use of the Bayard–Alpert (BA) gauge and in the interpretation of the data that it provides. This article is a practical guide to its use. Sections in boldface type provide such a guide and are followed in each instance by supplementary, detailed discussion of the rationale behind the guide. The topics addressed include gas pumping, by generation of ions, and by chemical interactions at the electron emitter; the change in gas composition by interaction at the electron emitter; and errors in pressure measurement including Barkhausen–Kurtz oscillations, electron-stimulated desorption, and the x-ray effect. Factors which dictate the specific BA gauge selection, such as the method used for outgas, and the selection of the electron emitter, are discussed.