10th International Aerosol Conference September 2 - September 7, 2018 America's Center Convention Complex St. Louis, Missouri, USA
Abstract View
Performance Comparison of Field Portable Instruments to the Scanning Mobility Particle Sizer Using Monodispersed and Polydispersed Sodium Chloride Aerosols
EVANLY VO, Matthew Horvatin, Ziqing Zhuang, NIOSH
Abstract Number: 219 Working Group: Instrumentation
Abstract The aims of this study were to 1) evaluate the performance of portable aerosol instruments, including the handheld condensation particle counter (CPC), the portable aerosol mobility spectrometer (PAMS), the optical particle sizer (OPS), and NanoScan scanning mobility particle sizer (NanoScan SMPS), regarding their utility for evaluating respirator protection in nanotechnology workplaces and 2) to compare the measurements made with the handheld CPC, PAMS, OPS, and NanoScan SMPS with those measured with the reference SMPS.
Performance was evaluated in terms of particle concentration and particle size distributions using monodispersed and polydispersed NaCl aerosols. Monodispersed aerosols were controlled at the approximate concentration of 1x105 particles/cm3. Four monodispersed particle sizes of 30, 60, 100, and 300 nm were selected and classified for the monodispersed aerosol test. Three different steady-state concentration levels (low, medium, and high: approximately 8x103, 5x104, and 1x105 particles/cm3, respectively) were selected for the polydispersed aerosol test. Particle concentration and size distributions measured with the portable aerosol instruments were compared with those measured with the reference SMPS. For all four monodispersed aerosol sizes, particle concentrations measured with the NanoScan SMPS were within 13% of those measured with the reference SMPS. Particle concentrations measured with the PAMS were within 25% of those measured with the reference SMPS. Concentrations measured with the handheld CPC were within 30% of those measured with the reference SMPS. For the polydispersed aerosols, the particle sizes and concentrations measured with the NanoScan OPS compared most favorably with those measured with the reference SMPS for the three concentration levels of low, medium, and high (concentration deviations ≤ 10% for all three concentration levels; deviations of particle size ≤ 4%). Although the particle size comparability between the PAMS and the reference SMPS was quite reasonable with the deviations within 10%, the polydispersed particle concentrations measured with the PAMS were within 36% of those measured with the reference SMPS.
While further studies are needed to determine how to wear and operate these portable instruments under simulated workplace conditions or in a real working environment, this study provided the advantages and limitations of each portable instrument and therefore results from this study can be used, with appropriate caution, when selecting a suitable portable instrument for aerosol particle measurement in nanotechnology workplaces.