Apparatus for measuring the partial pressure of gases or vapors

Abstract From the Canadian patent

An apparatus comprising a chemically sensitive sensor material, having an electrical resistance or dielectric constant which changes under the effect of the gases or vapors. According to the invention this sensor material, which, comprises either hydrophobic metal complexes or a mixture of, at least one phthalide and at least one acidic compound serves, as resistance or as dielectric material. These sensor materials change their ion mobility and/or their ionic concentration under the effect of gases or vapors thereby, changing their resistance or capacitance. The change in resistance or the change in capacitance can expediently be converted into a frequency change by a multivibrator. Thus …