02767 IUPAC Gold Book - helium ionization detector 10.1351/goldbook.H02767 H02767 current 1 A weak beta source and a high potential raise the helium atom of the carrier gas to a metastable state. All other substances having an ionization potential lower than \(18\ \rm{eV}\) 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 \(10\ \rm{ppmv}\). It has a linear range of about \(10^{2}\) but is somewhat unstable and requires great care to ensure the helium purity and to eliminate all leaks in the system. carrier gas https://goldbook.iupac.org//terms/view/C00863 ionization potential https://goldbook.iupac.org//terms/view/I03208 linear range https://goldbook.iupac.org//terms/view/L03558 metastable https://goldbook.iupac.org//terms/view/M03872 unstable https://goldbook.iupac.org//terms/view/U06569 PAC, 1990, 62, 2167. 'Glossary of atmospheric chemistry terms (Recommendations 1990)' on page 2191 (https://doi.org/10.1351/pac199062112167) https://goldbook.iupac.org/terms/view/H02767/html https://goldbook.iupac.org/terms/view/H02767/json https://goldbook.iupac.org/terms/view/H02767/plain Citation: 'helium ionization detector' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. 10.1351/goldbook.H02767 The IUPAC Gold Book is licensed under Creative Commons Attribution-ShareAlike CC BY-SA 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) for individual terms. If you are interested in licensing the Gold Book for commercial use, please contact the IUPAC Executive Director at executivedirector@iupac.org . The International Union of Pure and Applied Chemistry (IUPAC) is continuously reviewing and, where needed, updating terms in the Compendium of Chemical Terminology (the IUPAC Gold Book). Users of these terms are encouraged to include the version of a term with its use and to check regularly for updates to term definitions that you are using. 2026-06-20T08:14:41+00:00