Patent ID: 8089367

Claim:
An air monitoring apparatus comprising: a housing, said housing comprising at least one fluid passage to permit a fluid to enter said housing; and a constituent detection device positioned in said housing, said detection device comprising: at least one electrode positioned on a body; at least one coating applied onto said at least one electrode and said body forming a film covering said at least one electrode and said body, said at least one coating comprising at least one material selected from the group consisting of, a dye, organic ionic materials, inorganic ionic materials, conductive polymers, nonconductive polymers, cationic polymers, anionic polymers, inorganic sorbents, and small organic molecules; a power supply electrically coupled to said at least on electrode, said power supply configured to generate an AC signal; and a logic circuit electrically coupled to said power supply, said logic circuit configured to detect a change in at least one of impedance magnitude and a phase shift angle magnitude as a function of applied frequency when said detection device contacts at least one fluid constituent contained in the fluid flowing into said housing through said at least one fluid passage or when said detection device contacts at least one constituent in a solid wherein at least one of chemical and material properties of the solid change as a function of fluid flowing into said housing through said at least one fluid passage.