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
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
and
.
It has a
linear range of about
but is somewhat
unstable and requires great care to ensure the helium purity and to eliminate all leaks in
the system.
Source:
PAC, 1990, 62, 2167
(Glossary of atmospheric chemistry terms (Recommendations 1990))
on page 2191
Cite as:
IUPAC. Compendium of Chemical Terminology, 2nd ed. (the "Gold Book"). Compiled by
A. D. McNaught and A. Wilkinson. Blackwell Scientific Publications, Oxford (1997).
XML on-line corrected version: http://goldbook.iupac.org (2006-) created by M. Nic,
J. Jirat, B. Kosata; updates compiled by A. Jenkins. ISBN 0-9678550-9-8.
https://doi.org/10.1351/goldbook.
