ABSTRACT
The designs of the ionization gauges with hot filaments are derived from the concept of the conventional vacuum triodes. The ion current can be increased via the significant elongation of electron trajectories, which can be obtained by inverting the function of electrodes. The interchange of the electrode functions provides the higher gauge sensitivity. In consistence with effort to increase the sensitivity and expand the range of measured pressures, different constructions of hot filament ionization gauges have been developed. The performance of Bayard–Alpert gauges is considerably affected by filament position and electrical fields near the filament. The cylindrical design of the hot filament gauges has been used in different modifications. The operation of the vacuum triode is based on moderating the passage of thermionic electrons from a hot filament cathode to an anode by electronic voltage-gating on a grid electrode. The amplification of electronic signals is obtained by modulating the electric current of electrons between the cathode and anode.
