Date of download: 6/1/2016 Copyright © 2016 SPIE. All rights reserved.
Schematic view of the pulsed PA spectrometer.
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From: Investigation of spectral dependence of shortwave radiation absorption by ambientaerosol using time-resolved photoacoustic technique
Opt. Eng. 2005;44(7):071203-071203-11. doi:10.1117/1.1955327
Date of download: 6/1/2016 Copyright © 2016 SPIE. All rights reserved.
Calibration plot for the pulsed PA spectrometer.
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From: Investigation of spectral dependence of shortwave radiation absorption by ambientaerosol using time-resolved photoacoustic technique
Opt. Eng. 2005;44(7):071203-071203-11. doi:10.1117/1.1955327
Date of download: 6/1/2016 Copyright © 2016 SPIE. All rights reserved.
Schematic view of the parabolic reflector PA cell: cell body (1), translation paraboloid (2), rotation paraboloid (3), laser beam (4),microphone (5), and wideband amplifier (6).
Figure Legend:
From: Investigation of spectral dependence of shortwave radiation absorption by ambientaerosol using time-resolved photoacoustic technique
Opt. Eng. 2005;44(7):071203-071203-11. doi:10.1117/1.1955327
Date of download: 6/1/2016 Copyright © 2016 SPIE. All rights reserved.
(a) Calculated amplitude and (b) duration of the compression pulse as functions of laser beam radius for three heat releaseprocesses (Gaussian, exponential, and rectangular) with duration of 5×10−8s (short dashed dotted lines) and for exponential (solidlines), Gaussian (dashed lines), and rectangular (short dashed lines) heat release processes with duration of 10−6s.
Figure Legend:
From: Investigation of spectral dependence of shortwave radiation absorption by ambientaerosol using time-resolved photoacoustic technique
Opt. Eng. 2005;44(7):071203-071203-11. doi:10.1117/1.1955327
Date of download: 6/1/2016 Copyright © 2016 SPIE. All rights reserved.
Comparison of the PA signals produced due to Nd:YAG laser radiation (1.064μm) absorption by ambient aerosol (curve 1), rubylaser radiation (0.694380μm) absorption by water vapor (curve 2), and ruby laser radiation (0.694300μm) absorption by ambientaerosol (curve 3). Signal 2 is divided by a factor 20. The value of aerosol absorption coefficient is determined with the use of formulak=α−1UabsE−1, where α is the PA spectrometer sensitivity, Uabs is the measured amplitude of PA detector signal, and E is themeasured laser pulse energy.
Figure Legend:
From: Investigation of spectral dependence of shortwave radiation absorption by ambientaerosol using time-resolved photoacoustic technique
Opt. Eng. 2005;44(7):071203-071203-11. doi:10.1117/1.1955327
Date of download: 6/1/2016 Copyright © 2016 SPIE. All rights reserved.
Amplitude of the PA detector signal generated due to ambient aerosol light absorption versus the energy of Nd:YAG laser pulse(λ=1.064μm).
Figure Legend:
From: Investigation of spectral dependence of shortwave radiation absorption by ambientaerosol using time-resolved photoacoustic technique
Opt. Eng. 2005;44(7):071203-071203-11. doi:10.1117/1.1955327
Date of download: 6/1/2016 Copyright © 2016 SPIE. All rights reserved.
Correlation of BC concentration and aerosol absorption coefficient at (a) 0.532μm, (b) 1.064μm, and (c) 0.694μm. Approximation ofthese experimental data by the linear regression gives the values of aerosol absorption efficiency for corresponding wavelengths:σ(0.532μm)=5.49±0.44m2g−1, σ(1.064μm)=2.87±0.20m2g−1, and σ(0.694μm)=4.46±0.07m2g−1.
Figure Legend:
From: Investigation of spectral dependence of shortwave radiation absorption by ambientaerosol using time-resolved photoacoustic technique
Opt. Eng. 2005;44(7):071203-071203-11. doi:10.1117/1.1955327
Date of download: 6/1/2016 Copyright © 2016 SPIE. All rights reserved.
Absorption efficiency of light absorbing aerosols as function of wavelength. The PA measurements data analyzed in the paper ofMoosmüller et al. (triangles) are approximated by function y=1.60λ−2.71. The values for laboratory generated aerosols are shownas open triangles, and those for ambient aerosol are shown as solid triangles. Data of the present PA measurements (squares) areapproximated by function y=3.1×λ−0.92.
Figure Legend:
From: Investigation of spectral dependence of shortwave radiation absorption by ambientaerosol using time-resolved photoacoustic technique
Opt. Eng. 2005;44(7):071203-071203-11. doi:10.1117/1.1955327
Date of download: 6/1/2016 Copyright © 2016 SPIE. All rights reserved.
Comparison of the aethalometer measurements of BC mass concentration and PA measurements of aerosol light absorptioncoefficient at (a) 0.532μm, (b) 1.064μm, and (c) 0.694μm. The latter in time points correspond to the instrument’s readings for airsampled through aerosol filters.
Figure Legend:
From: Investigation of spectral dependence of shortwave radiation absorption by ambientaerosol using time-resolved photoacoustic technique
Opt. Eng. 2005;44(7):071203-071203-11. doi:10.1117/1.1955327
Date of download: 6/1/2016 Copyright © 2016 SPIE. All rights reserved.
Correlation of BC concentration and aerosol absorption coefficient at 1.064 and 0.532μm. The aerosol light absorption efficiency at0.532μm is higher than one at 1.064μm by factor 1.89.
Figure Legend:
From: Investigation of spectral dependence of shortwave radiation absorption by ambientaerosol using time-resolved photoacoustic technique
Opt. Eng. 2005;44(7):071203-071203-11. doi:10.1117/1.1955327
Date of download: 6/1/2016 Copyright © 2016 SPIE. All rights reserved.
Water vapor absorption spectrum in the tuning range of the ruby laser at partial pressure of water vapor P(H2O)=10.3torr and totalpressure of wet air P=736torr where circles are PA measurements and the solid line is for calculations with the use of HITRAN-96.
Figure Legend:
From: Investigation of spectral dependence of shortwave radiation absorption by ambientaerosol using time-resolved photoacoustic technique
Opt. Eng. 2005;44(7):071203-071203-11. doi:10.1117/1.1955327
