Pressure Sensor Technologies
Intro: Pressure sensing technology that we use in the lab mostly revolves around ionic and thermal applications of gas properties. Ion and thermal couple gauges respectively.
Ion Gauges: A filament is charged and produces free electrons. These electrons roam free in the low pressure system until they bombard a gas atom. This bombardment knocks off an electron from the gas atom, creating a cation. This cation is attracted to a collector which completes a circuit between the filament and the collector. This current is measured and is directly related to the density of the remaining gas and subsequently, its pressure.
Thermocouple Gauge (TCG): A heated filament is placed into the low pressure system and allowed to cool. The rate of heat loss is directly related to gas density and subsequently, pressure.