A sensing system includes a housing having an inlet for receiving a fluid flow from a source and an outlet with for directing a fluid flow from the housing, wherein a longitudinal axis transverses a center of the inlet and the outlet; a flow conduit disposed in the housing and in fluid communication with the inlet and the outlet, the flow conduit having a cross-sectional area that is substantially the same as a cross-sectional area of the inlet and the outlet, wherein a first length of the flow conduit along a second axis, and wherein the first axis and the second axis are perpendicular to the longitudinal axis; a light source for illuminating the fluid in the flow conduit along the first axis; and a sensor for detecting contaminants in the fluid.