Feb 6, 2015
Ion gauges on one of our deposition systems. Ionization gauges are commonly used to measure pressure in high vacuum. They look and operate very much like a light bulb. Electrons are emitted from a central heated filament (the glowing part) and accelerated toward a helical wire or "grid" around the filament. Some of these electrons collide with gas molecules and ionize them. The ions are then attracted to a collector filament, creating a current which can be measured. The magnitude of the ion current depends on the pressure and composition of the gas.