using a hygroscopic substance (for example, diphosphorus pentaoxide,
) which is transformed into an electrolyte (phosphoric acid,
in contact with the moisture in the gas. The electrolyte (phosphoric acid) is electrolysed
continuously and the electrolysis current is measured. At a constant flow of the gas
to be analysed, the electrolysis current is a linear function of the water concentration.
PAC, 1990, 62, 2167
(Glossary of atmospheric chemistry terms (Recommendations 1990))
on page 2195
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