helium ionization detector

in gas chromatography
A weak beta source and a high potential raise the helium atom of the @[email protected] to a @[email protected] state. All other substances having an @[email protected] lower than \(18\ \text{eV}\) are ionized, and the current that results is used to measure the components. The detector is usually employed to measure inorganic compounds at concentrations between \(0.1\) and \(10\ \text{ppmv}\). It has a @[email protected] of about \(10^{2}\) but is somewhat @[email protected] and requires great care to ensure the helium purity and to eliminate all leaks in the system.
PAC, 1990, 62, 2167. (Glossary of atmospheric chemistry terms (Recommendations 1990)) on page 2191 [Terms] [Paper]