Abstract: A visual indicator device and method for determining the presence of oily contaminants in an aqueous stream are provided. The device includes a filtration status chamber for receiving and discharging the aqueous stream, and a transparent wall enabling viewing of the chamber interior. A fluid-pervious filtration media within the chamber is infused with an absorption composition at which the contaminant on contact with the media is immobilized. The media has a surface viewable through a transparent wall of the filtration status chamber, and the stream flow path causes the stream to impinge at the media via the surface, whereby the contaminants collect selectively at the media surface and are highly visible through the transparent wall.

Abstract: A visual indicator device and method for determining the presence of oily contaminants in a gaseous stream are provided. The device includes a filtration status chamber for receiving and discharging the gaseous stream, and a transparent wall enabling viewing of the chamber interior. A fluid-pervious filtration media within the chamber is infused with an absorption composition at which the contaminant on contact with the media is immobilized. The media has a surface viewable through a transparent wall of the filtration status chamber, and the stream flow path is such as to cause the stream to impinge at the media via the said surface, whereby the contaminants collect selectively at the media surface and are therefore highly visible through the transparent wall.