An ionization chamber is used to measure the ionizing radiation in an environment. It works by collecting the charge that is produced when radiation ionizes the gas inside the chamber. This charge is then measured to determine the level of radiation present.

Photoelectric or, more commonly, an ionization chamber

A multi-wire chamber (or just wire chamber) is a type of proportional counter that detects charged particles and photons, by means of gaseous ionization detection of particles of ionizing radiation.

An ionization gauge pressure sensor measures the pressure of a gas by determining the number of gas ions present in a vacuum chamber. As gas pressure increases, more gas ions are formed through ionization, which the sensor can detect and convert into a pressure reading.