an absolute reference aerosol sampler system and method based on isokinetic and isoaxial sampling principles wherein the position of a collection inlet for an aerosol sampling head is adjusted relative to the actual wind direction in real time . in addition , flow rate of the air at a collection inlet within the absolute - reference sampler is matched to the real time actual wind speed . these adjustments and controls enable the absolute reference sampler system to obtain particulate samples from the immediate environment without biasing the size distribution in any manner , resulting in a fully unbiased , representative sample .