초록 ▼

The present invention provides a disposable laminated colorimetric gas monitoring wafer for sensing and monitoring exposure to a selected gas. Opposed gas impermeable layers, such as plastic, generally enclose a carrier medium, such as a sorbent, which carries a color-forming chromophore composition

The present invention provides a disposable laminated colorimetric gas monitoring wafer for sensing and monitoring exposure to a selected gas. Opposed gas impermeable layers, such as plastic, generally enclose a carrier medium, such as a sorbent, which carries a color-forming chromophore composition that changes color in response to exposure to a selected gas. A porous, hydrophobic membrane exposed through an opening in one outer plastic layer, overlays the carrying medium and the chromophore composition. Wind and moisture effects are reduced by the porous membrane, and the porous hydrophobic membrane also prevents relative humidity from effecting the color of the chromophore composition.

대표청구항 ▼

A colorimetric gas monitoring wafer for sensing and measuring gas concentrations and/or cumulative exposure dose of a selected gas comprising a gas impermeable base; a color-forming chemical which changes color in response to exposure to a selected gas disposed over said base; a gas impermeable cove

A colorimetric gas monitoring wafer for sensing and measuring gas concentrations and/or cumulative exposure dose of a selected gas comprising a gas impermeable base; a color-forming chemical which changes color in response to exposure to a selected gas disposed over said base; a gas impermeable cover secured to said base for encapsulating said color-forming chemical; a carrier medium disposed over said base and encapsulated by said cover, and wherein said color-forming chemical is carried on said carrier medium; an opening formed in said cover for allowing ambient air to enter the wafer and contact said color-forming chemical; a gas permeable hydrophobic membrane which is a barrier to water vapor while allowing comparatively free passage of non-polar gases overlying said color-forming chemical and aligned with said opening so that the ambient air must pass through the membrane to reach said color-forming chemical; and means defining a transparent measurement area on said base located opposite said opening in said cover for viewing the change in color of said color-forming chemical as a result of contact by the ambient air.