Nakayama, T., H. Suzuki, S. Kagamitani, Y. Ikeda, A. Uchiyama, and Y. Matsumi, 2015: Characterization of a three wavelength photoacoustic soot spectrometer (PASS-3) and a photoacoustic extinctiometer (PAX). J. Meteor. Soc. Japan, 93, 285-308.
- Performance of two commercially available instruments, three-wavelength photoacoustic soot spectrometer (PASS-3, λ = 405, 532, 781 nm) and photoacoustic extinctiometer (PAX, λ = 375nm), for the measurement of the light absorption and scattering coefficients of aerosols based on photoacoustic spectroscopy and reciprocal nephelometry were characterized.
- A significant particle size dependency was observed for the calibration factors for scattering measurements at 532 nm, likely due to a combination of differences in the polarization states of the lasers relative to the scattering planes and the large truncation angle, while no significant particle size dependencies were observed at 375, 405, and 781 nm (Fig. 1).
- The calibration factors for absorption measurements determined based on the light absorption of NO2 molecules at 375 and 405 nm were 48 and 36% smaller than those for the poly-disperse soot particles, likely due to the influence of photolysis of NO2, although good agreement was observed at 532 nm (Fig. 2).