TY - BOOK
T1 - Characterization and Development of Electrical Methods for Aerosol Measurement
AU - Salo, Laura
PY - 2023/6
Y1 - 2023/6
N2 - Aerosol particle research is motivated by the negative influence of particles on human health and air quality, as well as their impact on climate. Despite overwhelming evidence of their serious potential to do harm, only very few places have particle concentrations that do not exceed guideline values. To reduce particle pollution, we must also understand their sources. For these reasons, air quality monitoring is still of utmost importance. The World Health Organization provides guideline values for particle mass concentration, but many studies now point out that particle surface area concentration and particle number concentration may be crucial in determining the toxicity of a particle population. This thesis presents aerosol measurement methods which are based on the electrical detection of aerosol particles, building up to the presentation of a novel electrical measurement method. The background section provides an overview of why different methods and metrics are necessary for aerosol measurement, and summarizes current knowledge on particle charging, both naturally in ambient air and through purposeful diffusion charging. The results first present electrical measurement methods in comparison to traditional filter-based techniques. Then electrical methods are employed in different surroundings to measure lung depositing surface area (LDSA) and the LDSA concentration is compared to the particle mass concentration. Cheaper, sensor-type instruments for LDSA measurement are also evaluated in comparison to more expensive research grade instrumentation. Finally, the thesis presents the new measurement method, based on employing the natural charge of particles. Based on the results presented in this thesis, sensor-type measurements are dependable for long-term particle monitoring; however, more intensive measurements are required as well, and sensors must be chosen to fit the monitored environment. For example, measurements in a roadside environment near Delhi and in Helsinki revealed that both particle concentrations and particle distributions differ significantly. Employing the novel measurement method in highly polluted air revealed that particle charging with a charger is unnecessary for detection, as the naturally occurring charge is enough for detection and monitoring.
AB - Aerosol particle research is motivated by the negative influence of particles on human health and air quality, as well as their impact on climate. Despite overwhelming evidence of their serious potential to do harm, only very few places have particle concentrations that do not exceed guideline values. To reduce particle pollution, we must also understand their sources. For these reasons, air quality monitoring is still of utmost importance. The World Health Organization provides guideline values for particle mass concentration, but many studies now point out that particle surface area concentration and particle number concentration may be crucial in determining the toxicity of a particle population. This thesis presents aerosol measurement methods which are based on the electrical detection of aerosol particles, building up to the presentation of a novel electrical measurement method. The background section provides an overview of why different methods and metrics are necessary for aerosol measurement, and summarizes current knowledge on particle charging, both naturally in ambient air and through purposeful diffusion charging. The results first present electrical measurement methods in comparison to traditional filter-based techniques. Then electrical methods are employed in different surroundings to measure lung depositing surface area (LDSA) and the LDSA concentration is compared to the particle mass concentration. Cheaper, sensor-type instruments for LDSA measurement are also evaluated in comparison to more expensive research grade instrumentation. Finally, the thesis presents the new measurement method, based on employing the natural charge of particles. Based on the results presented in this thesis, sensor-type measurements are dependable for long-term particle monitoring; however, more intensive measurements are required as well, and sensors must be chosen to fit the monitored environment. For example, measurements in a roadside environment near Delhi and in Helsinki revealed that both particle concentrations and particle distributions differ significantly. Employing the novel measurement method in highly polluted air revealed that particle charging with a charger is unnecessary for detection, as the naturally occurring charge is enough for detection and monitoring.
M3 - Doctoral thesis
SN - 978-952-03-2929-7
T3 - Tampere University Dissertations - Tampereen yliopiston väitöskirjat
BT - Characterization and Development of Electrical Methods for Aerosol Measurement
PB - Tampere University
CY - Tampere
ER -
