Title
Angular illumination and truncation of three different integrating nephelometers: Implications for empirical, size-based corrections
Author
Muller, T.
Nowak, A.
Wiedensohler, A.
Sheridan, P.
Laborde, M.
Covert, D.S.
Marinoni, A.
Imre, K.
Henzing, B.
Roger, J.C.
Dos Santos, S.M.
Wilhelm, R.
Wang, Y.Q.
de Leeuw, G.
TNO Bouw en Ondergrond
Publication year
2009
Abstract
Integrating nephelometers are widely used for monitoring and research applications related to air pollution and climate. Several commercial versions of the instrument are available and are in wide use in the community. This article reports on results from a calibration and intercomparison workshop where several units of the three most widely used nephelometer models were tested with respect to their CO2 calibration accuracy and stability and non-idealities of their angular illumination function. Correction factors that result from the non-ideal illumination due to truncation of the sensing volumes in the near-forward and near-backward angular ranges and for non-Lambertian illumination from the light sources are presented, in particular for two models that have not previously been tested in this respect. The correction factors ranged from 0.95 to 1.15 depending on the model of nephelometer and aerosol size distribution. Recommendations for operational data analysis in context of these and previous performance tests are presented.
Subject
Urban Development
Environment
Built Environment
Aerosol size distributions
Angular range
Calibration accuracy
Correction factors
Intercomparison
Lambertian illumination
Non-idealities
Operational data
Performance tests
Air quality
Calibration
Light
Light sources
Nephelometers
carbon dioxide
air pollution
angular illumination
article
calibration
data analysis
diagnostic accuracy
drug stability
illumination
intermethod comparison
light scattering
nephelometry
nonhuman
priority journal
Lambertia
To reference this document use:
http://resolver.tudelft.nl/uuid:002cea45-995d-4513-9641-0c20abe16f5f
DOI
https://doi.org/10.1080/02786820902798484
TNO identifier
241584
ISSN
0278-6826
Source
Aerosol Science and Technology, 43 (6), 581-586
Document type
article