Control of hot-filament ionization gauge emission current: mathematical model and model-based controller
Nikolai Donkov, Wolfram H. Knapp · Measurement Science and Technology · 1997
The lack of adequate models for feedback-controlled emission current in hot-filament cathode ionization gauges (IGs) makes it difficult to achieve precision control over a wide range of emission currents (0.01 - 10 mA). A nonlinear mathematical model for transforming the filament heating power into emission current is developed. Experimental and theoretical results are shown. An electron emission regulator is described which was designed for use in the calibration of IGs, mass spectrometers and vapour rate measurements with IGs.