Patent ID: 8024986

Claim:
An environmental sensing unit responsive to a plurality of parameters of a fluid in an interior of a duct defined by a closed interior surface of a duct wall having an exterior surface, said duct wall including a portion defining a single duct wall aperture extending substantially normal to said exterior surface and connecting said exterior surface to said interior surface, said sensing unit comprising: (a) an enclosure defining an enclosable enclosure volume and including a portion defining one enclosure aperture, said enclosure arranged for attachment to said exterior of said duct wall with said enclosure volume in fluid communication with said interior of said duct through said duct wall aperture and said one enclosure aperture; and (b) at least three sensors in contact with said fluid through said single duct wall aperture, at least one of said at least three sensors located within said enclosure volume and not in contact with said fluid in said interior of said duct and at least one of said sensors supported in said fluid in said interior of said duct.