Ionization gaugeIonization gauges are the most sensitive gauges for very low pressures (also referred to as hard or high vacuum). They sense pressure indirectly by measuring the electrical ions produced when the gas is bombarded with electrons. Fewer ions will be produced by lower density gases. The calibration of an ion gauge is unstable and dependent on the nature of the gases being measured, which is not always known. They can be calibrated against a McLeod gauge which is much more stable and independent of gas chemistry.
Ionization gaugeIonization gauges are the most sensitive gauges for very low pressures (also referred to as hard or high vacuum) They sense pressure ind.irectly by measuring the electrical ions produced when the gas is bombarded with electrons Fewer ions will be produced by lower density gases. The calibration of an ion gauge is unstable and dependent on the natur.e of the gases being measured, which is not always known. They can be calibrated against a McLeod gauge which is much more stable and independent of gas chemistry.