PILS

The Particle Into Liquid Sampler (PILS) was developed for rapid automated on-line and continuous measurement of ambient aerosol bulk composition. The general approach is based on earlier devices in which ambient particles are mixed with saturated water vapor to produce droplets easily collected by inertial techniques. The resulting liquid stream is analyzed with an ion chromatograph to quantitatively measure the bulk aerosol ionic components. In this instrument, a modified version of a particle size magnifier is employed to activate and grow particles comprising the fine aerosol mass. A single jet inertial impactor is used to collect the droplets onto a vertical glass plate that is continually washed with a constant water diluent flow of nominally 0.10 ml min-1. The flow is divided and then analyzed by a dual channel ion chromatograph. In its current form, 4.3 min integrated samples were measured every 7 min. The instrument provides bulk composition measurements with a detection limit of approximately 0.1 µg m-3 for chloride, nitrate, sulfate, sodium, ammonium, calcium, and potassium.