Absorption Coefficient of Particle-Laden Filters using the Laser Heating: Validation with Nigrosin
A novel laser-heating technique, referred to as the laser-driven thermal reactor, was used in conjunction with laser transmission to determine the absorption coefficient (and imaginary part of the refractive index) of aggregated particles on substrates (e.g., quartz-fiber filters) and of bulk samples. The novelty of this technique is that it is suitable for determining the absorptivity of individual particle aggregates and droplets at representative meteorological conditions. For this study, measurements were carried out with particle-laden quartz-fiber filters at process conditions (i.e., sample temperature, gas pressure, and composition) similar to those of other filter-based absorption techniques. To validate this technique, measurements were carried out with nigrosin and compared to values published in the archival literature. In addition, the absorptivity of nigrosin/water solution at different concentrations was compared with results obtained from an ultraviolet/visible spectrometer.
Absorption Coefficient of Particle-Laden Filters using the Laser Heating: Validation with Nigrosin, Aerosol Science and Technology, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=907480
(Accessed December 8, 2023)