Abstract: An air monitoring apparatus includes, in an exemplary embodiment, a housing having at least one fluid passage to permit a fluid to enter the housing, and a constituent detection device positioned in the housing. The detection device includes at least one electrode, a power supply electrically coupled to the at least on electrode, and a logic circuit electrically coupled to the power supply. The logic circuit is configured to detect a change in at least one of impedance magnitude and a phase shift angle magnitude over a range of frequencies when the detection device contacts at least one fluid constituent contained in the fluid flowing into the cartridge through the at least one fluid passage, or when the detection device contacts at least one constituent in a solid whose chemical and/or material properties change as a function of fluid flowing into the housing through the at least one fluid passage.

Abstract: An apparatus for detecting exposure to at least one hazardous substance is provided. The apparatus includes a body having a plurality of openings, and an attachment mechanism coupled to the body. Each opening is sized to receive a cassette for detecting the presence or absence of at least one hazardous substance. The cassette can include a colorimetric sensor having a base layer fabricated from a hydrophobic film, a colorimetric coating for covering the hydrophobic film, and at least one hydrophobic membrane for controlling the exposure of the specific substance to the colorimetric coating.

Abstract: An air monitoring apparatus includes, in an exemplary embodiment, a housing having at least one fluid passage to permit a fluid to enter the housing, and a constituent detection device positioned in the housing. The detection device includes at least one electrode, a power supply electrically coupled to the at least on electrode, and a logic circuit electrically coupled to the power supply. The logic circuit is configured to detect a change in at least one of impedance magnitude and a phase shift angle magnitude over a range of frequencies when the detection device contacts at least one fluid constituent contained in the fluid flowing into the cartridge through the at least one fluid passage, or when the detection device contacts at least one constituent in a solid whose chemical and/or material properties change as a function of fluid flowing into the housing through the at least one fluid passage.