AAAR 32nd Annual Conference
September 30 - October 4, 2013
Oregon Convention Center
Portland, Oregon, USA
Abstract View
Validation of a Personal Sampler’s Performance in Sampling Inorganic Acids According to OSHA Guideline
LIN SHOU, Danielle Hall, Yu-Mei Hsu, Alex Theodore, Chang-Yu Wu, Brian Birky, University of Florida
Abstract Number: 361 Working Group: Instrumentation and Methods
Abstract A personal sampling device has been developed to measure the true level of inorganic acidic gases and aerosols simultaneously in occupational environment that may have high acid aerosol mist and gas concentrations. It consists of a parallel impactor upstream, a porous membrane denuder (PMD) in the middle and a filter pack downstream. The parallel impactor, which has 4 parallel and separated impactors with different nozzle sizes, was designed to have a collection efficiency curve that approximates the ACGIH respirable curve. Experimental results proved that the prototype samplers followed closely the penetration characteristics for which it was designed. In the second stage, the PMD, which utilizes the high porosity of membrane material and a configuration of multiple parallel flow channels to compact the size, decrease the weight and increase gas collection efficiency, was used to remove gaseous compounds while allowing aerosol to pass through the section. Experimental results showed that the PMD’s collection efficiency for 10 ppm sulfur dioxide over 5 hours was higher than 97%. The sampling capacity of the personal sampler was tested by sampling a dynamically generated controlled test atmosphere containing H$_2SO$_4 at four times of the OSHA standard concentration (4 mg/m$^3) and 72% relative humidity at 20 °C. The personal sampler’s overall collection efficiency maintained above 93.9% for 10 hours, and the sampler had a capacity larger enough for 4 times of the OSHA standard. 23.2%±2.3%, 4.2%±0.3%, and 72.5%±2.1% of the feed were collected at the impactor, denuder and the filter pack, respectively. The personal sampler’s storage stability and its performance under low humidity and low concentration will be further tested according to the validation guidelines for air sampling methods published by OSHA (Occupational Safety and Health Administration), and experimental results will be updated at the conference.