Development of monitoring technology for airborne particulate matter.

Abstract

Particulate matter suspended in the air has adverse effects on human health. Its level of concentration is an important parameter in evaluating the degree of hazard it poses to the atmosphere. Conventional methods used in measuring particulate matter are often filter-based, which indicates some disadvantages because such a base requires labor and time. In this study, to achieve real-time measurements, a new electrical method was developed for measuring PM10 and PM2.5 concentrations. The basic principle is to electrically charge particles passing through the PM inlet using a corona charger and measure the currents created by charged particles to obtain the number concentration of particulate matter. A new type inlet based on the particle cup impactor configuration was designed and its performance was evaluated. A unipolar diffusion charger was developed and the charger's efficiency was determined experimentally in terms of Pn, which represents the penetration through the charger, P, times the average charge number acquired by a particle, n, for different particle sizes. The correlation was constructed between the PM 10 (or the PM2.5) mass concentrations and the electrical currents due to particles, which were charged by the diffusion charger.