Comparison of the SidePak™ personal monitor with the Aerosol Particle Sizer (APS)

The aim of this study was to compare the performance of the TSI Aerodynamic Particle Sizer (APS) and the TSI portable photometer SidePak™ to measure airborne oil mist particulate matter (PM) with aerodynamic diameters below 10 μm, 2.5 μm and 1 μm (PM10, PM2.5 and PM1). Three SidePaks™ each fitted with either a PM10, PM2.5 or a PM1 impactor and an APS were run side by side in a controlled chamber. Oil mist from two different mineral oils and two different drilling fluid systems commonly used in offshore drilling technologies were generated using a nebulizer. Compared to the APS, the SidePaks™ overestimated the concentration of PM10 and PM2.5 by one order of magnitude and PM1 concentrations by two orders of magnitude after exposure to oil mist for 3.3–6.5 min at concentrations ranging from 0.003 to 18.1 mg m−3 for PM10, 0.002 to 3.96 mg m−3 for PM2.5 and 0.001 to 0.418 mg m−3 for PM1 (as measured by the APS). In a second experiment a SidePak™ monitor previously exposed to oil mist overestimated PM10 concentrations by 27% compared to measurements from another SidePak™ never exposed to oil mist. This could be a result of condensation of oil mist droplets in the optical system of the SidePak™. The SidePak™ is a very useful instrument for personal monitoring in occupational hygiene due to its light weight and quiet pump. However, it may not be suitable for the measurement of particle concentrations from oil mist.