The Model HD-66A is a mobile “K-Flow” constant flow air sampler designed for use in nuclear power plants, research laboratories, production areas, and throughout industrial facilities where the collection of precise air samples is required on a continuous or semi-continuous basis. Its heavy duty vacuum pump and constant air flow regulator combination permits the collection of an air particulate sample at a constant flow rate until the ΔP across the filter paper exceeds the capability of the pump at that flow rate. (See datasheet)