Improved particle sampling techniques are needed to counter the disadvantages of traditional filter sampling and the limitations of those currently available. This study presents the development and evaluation of an Aerosol to Hydrosol Air Sampler (ATHAS). It consists principally of a steam generator, condenser and collector. ATHAS collects particles at the flow rate of 50 litres per minute through condensational growth followed by particle-containing droplets collection of combined impaction and centrifugal flow. Monodisperse polystyrene latex (PSL) particles ranging in size from 0.1 µm to 2 µm were used to test the performance of size dependent collection at the extreme condition of highly hydrophobic aerosols. Results show that the sampler has near 90–100% collection efficiency for supermicron PSL particles, and 65% and 50% for 0.5 and 0.1 µm particles, respectively. NaCl collection efficiency tests showed that the sampler has over 95% collection efficiency for soluble aerosols. The medium size and sampling flow make it suitable for field deployment with high potential for semi-continuous online chemical analysis.