Development and Evaluation of a Particle Deposition Measurement Method Based on a CCD Imaging Chip

Particle deposition on indoor surfaces has lately received great attention due to increasing concern about the effects of particle exposure on human health. In this study, we developed an easy and low-cost method of measuring the deposition amounts of different-sized particles and evaluated it through particle concentration measurement and theory calculation. First, a clean charge-coupled device (CCD) chip was exposed to air in order to receive the deposition of airborne particles. After sedimentation, images generated by the CCD of the deposited particles were analyzed, and the quantity of particles in each size range (> 2 µm) was identified based on the unique pixel sizes. Using a particle counter and a dust monitor, we also measured the concentrations of airborne particles with different sizes near the chip during sedimentation and compared them with the numbers of settled particles. The results show that the particle deposition can be quantified with this method and that a positive correlation exists between the deposition amounts and the particle number concentrations.