Secondary sampling device

Claim 1

A secondary sampling device for particulate matter, comprising a plurality of sample splitters arranged in series including a top sample splitter and a bottom sample splitter, each sample splitter, including: a substantially vertical inlet duct having a substantially vertical axis, an inlet in an upper portion of said duct providing an opening to said substantially vertical inlet duct, a first outlet duct and a second outlet duct below said inlet having substantially equal cross-sectional areas and both communicating with the inlet duct, wherein the center axes of the inlet duct and the outlet ducts are in the same plane and intersect at the same point and the angle between the inlet duct and the first outlet duct is substantially equal to the angle between the inlet duct and the second outlet duct and is greater than about one hundred degrees, a separating edge formed by the intersection of the two outlet ducts, and a first outlet and a second outlet providing openings for the first outlet duct and second outlet respectively wherein particulate matter enters the secondary sampling device through the inlet of the top sample splitter, the inlet of each subsequent sample splitter joins the first outlet of the preceding sample splitter, and sample is withdrawn from the first outlet of the bottom sample splitter, and the plane of the axes of the inlet and outlet ducts of each sample splitter is substantially vertical and is substantially perpendicular to the same planes of adjacent sample splitters.