Calibration of high flow rate thoracic-size selective samplers

Abstract

High flow rate respirable size selective samplers, GK4.126 and FSP10 cyclones, were calibrated for thoracic-size selective sampling in two different laboratories. The National Institute for Occupational Safety and Health (NIOSH) utilized monodisperse ammonium fluorescein particles and scanning electron microscopy to determine the aerodynamic particle size of the monodisperse aerosol. Fluorescein intensity was measured to determine sampling efficiencies of the cyclones. The Health Safety and Laboratory (HSL) utilized a real time particle sizing instrument (Aerodynamic Particle Sizer) and poly-disperse glass sphere particles and particle size distributions between the cyclone and reference sampler were compared. Sampling efficiency of the cyclones were compared to the thoracic convention defined by the American Conference of Governmental Industrial Hygienists (ACGIH)/Comité Européen de Normalisation (CEN)/International Standards Organization (ISO). The GK4.126 cyclone showed minimum bias compared to the thoracic convention at flow rates of 3.5 l min−1 (NIOSH) and 2.7–3.3 l min−1 (HSL) and the difference may be from the use of different test systems. In order to collect the most dust and reduce the limit of detection, HSL suggested using the upper end in range (3.3 l min−1). A flow rate of 3.4 l min−1 would be a reasonable compromise, pending confirmation in other laboratories. The FSP10 cyclone showed minimum bias at the flow rate of 4.0 l min−1 in the NIOSH laboratory test. The high flow rate thoracic-size selective samplers might be used for higher sample mass collection in order to meet analytical limits of quantification.

Sampling Efficiency and Performance of Selected Thoracic Aerosol Samplers

“…The experimental D 50 started to deviate from the fitted curve at lower flow rates. This was confirmed by new HSL data of Thorpe published in Lee et al (2016). Fig.…”

Laboratory comparison of new high flow rate respirable size-selective sampler

“…The recommended flow rate of the GK4.162 for thoracic size-selective sampling has been reported by three different laboratories. [19,28] …”

“…[2,18,19] The top plate of the chamber was modified to allow a Kr-85 aerosol neutralizer (Model 3054A, TSI Inc.) to be used in the drying column. At least seven different sizes of monodisperse ammonium fluorescein aerosols were generated using a vibrating orifice aerosol generator (VOAG, Model 3450, TSI Inc.) at a range of testing flow rates.…”

“…At least seven different sizes of monodisperse ammonium fluorescein aerosols were generated using a vibrating orifice aerosol generator (VOAG, Model 3450, TSI Inc.) at a range of testing flow rates. [2,19,20] Aerodynamic particle size, particle concentration, and geometric standard deviation (GSD <1.1) were measured with an APS (Model 3321, TSI Inc.). The geometric mean of each particle size distribution measured by the APS was used as the aerodynamic diameter.…”

A collection of experimental data for aerosol monitoring cyclones

“…New aerosol monitoring cyclones are still needed to meet new challenges in both personal and ambient aerosol monitoring. The challenge, for example, of monitoring personal exposure to hazardous dusts at very low concentrations requires compact, lightweight cyclones that operate at high flow rates (Lee et al 2010(Lee et al , 2016. Separating diesel exhaust particles from co-present mineral particles in a mixed aerosol requires cyclones with a precise, sub-micron cut point that remains stable under high dust loadings (Cauda et al 2014).…”