Environmental sampling device

Claim 1

In combination with a portable means for providing a flow of dust laden air, a portable sampling device adapted for attachment to a worker's apparel for receiving a flow of dust laden air from said portable means and collecting air-borne dust samples therefrom, said portable sampling device comprising a first housing member having an inlet for receiving a dust laden air sample, a chamber communicating with said inlet and an annular recessed end portion opposite said inlet said chamber having a length which is about 13 times the diameter of said inlet and an inner diameter which is about 6.75 times the diameter of said inlet; a second housing member arranged adjacent to and in-line with said first housing member having an annular recessed portion adjacent the recessed portion of said first housing member to define an annular groove, a chamber within said second housing member having a length about 35% shorter than the length of the chamber of said first housing member communicating with the chamber of said first housing member, and an outlet; a closely engaging pair of ring-shaped members arranged in said annular groove; and a dust collecting membrane being supportably engaged only peripherally between said ring-shaped members, the diameter of the inner surfaces of said chambers and said ring-shaped members being essentially the same so as to provide a smooth surfaced passageway.