Ambient aerosol sampling inlet for flow rates of 100 and 400 l/min

Abstract

New bioaerosol sampling inlets were designed and tested that have nominal exhaust flow rates of 100 L/min to 400 L/min, and which have internal fractionators and screens to scalp large, unwanted particles and debris from the transmitted size distribution. These units consist of the same aspiration section, which is a 100 L/min Bell Shaped Inlet (BSI-100), and different pre-separators. The pre-separators are called the IRI-100 (Inline Real Impactor) with an exhaust flow rate of 100 L/min, the IRI-400 (exhaust flow rate of 400 L/min), the IVI-300 (Inline Virtual Impactor for a flow rate of 300 L/min) and the IVI-400. These units were tested in a wind tunnel at speeds of 2, 8, and 24 km/hr with particle sizes between 3 and 20 μm AD (aerodynamic diameter). The units show wind independent characteristics over the range of wind speeds tested. The aspiration section of the BSI-100 has greater than 85% penetration for particle sizes ≤ 10 μm AD. The IRI-100, IRI-400, IVI-300 and IVI-400, when combined with the BSI-100 all provide cutpoints of 11 ± 0.5 μm AD.