ZEMCH 2019 International Conference Proceedings April.2020 | Page 281
(c)
(d)
(e)
(f)
Figure 1. Chromaticity diagram of three different samples, household dust, soil dust, and pine
tree pollen. All dots are chromaticity values (Y, x, y) and only x, y coordinates are denoted. Each
figure is listed as: (a) as prepared (○) and water added (□) household dust; (b) as prepared (○) and
Refractive Index Liquid (RIL) added (▲) household dust; (c) as prepared (○) and water added (□) soil
dust; (d) as prepared (○) and RIL added (▲) soil dust; (e) as prepared (○) and water added (□) pine
tree pollen; (f) as prepared (○) and RIL added (▲) pine tree pollen.
Meanwhile, other yellowish and grey powders were detected at lower intensity. In addition,
overall chromaticity values for yellowish powders were observed to shift into yellow region in diagram,
upper left direction from central white region. For water and refractive index liquid added cases,
obvious differences in chromaticity values were observed. In figure 1‐a) and 1‐b) Household dust
revealed more shift in yellow and red region, which correspond to long wavelength range in light
spectrum. However, illite soil powder in figure 1‐c) and 1‐d) was detected to have more change in red
and green region. In case of pollen, not significant change in chromaticity values under additives. For
talc and gypsum powders, significant shift for talc was observed only for refractive index liquid case
and chromaticity values are centered to white than any other samples. It is well described in previous
study and means that more white light is reflected to chromameter [7]. In comparison with talc, same
experiments were executed for gypsum powder as shown in figure 2‐c) and d). Under chromameter
measurement, no noticeable difference was observed. It means that similar color and particle shape
does not differentiate the type of particle.
Optical Sensing Assistance to Enhance Particulate Contaminants Detection
for Indoor Air Quality Monitoring
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