An aerosol sampling intake configured to exclude particles generally greater than 20 microns AD and capture particles of less than about 10 microns AD with high efficiency, independent of weather conditions, through which air is sampled by suction. The intake combines an omnidirectional horizontal segment with diffuser and elbow, the elbow transitioning flow to a vertical segment, the vertical segment with overhanging lip, the centrifugal impactor for self-cleaning operation, thus relieving the dual problems of re-entrainment of particles bouncing from the impactor surface and fouling by particles sticking to the impactor surface. The device is adapted for use on moving vehicles, for sampling at increased windspeeds, or for sampling in rain.