Premium
Characterization of Airborne Fibers via Fraunhofer Theory: Examination of the Validity of Fraunhofer Theory Using the Exact Scattering Theory MMP
Author(s) -
Sagehorn Henning,
List Joachim,
Wiegand Till,
Weichert Reiner,
Wriedt Thomas
Publication year - 2001
Publication title -
particle and particle systems characterization
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.877
H-Index - 56
eISSN - 1521-4117
pISSN - 0934-0866
DOI - 10.1002/1521-4117(200107)18:2<55::aid-ppsc55>3.0.co;2-#
Subject(s) - characterization (materials science) , scattering , optics , physics
Owing to the health hazard of respirable airborne fibers, there is great interest in detectors able to monitor fibers on‐line. This paper features such an optical fiber detector which is based on Fraunhofer theory for the estimation of fiber size. Because Fraunhofer theory is not an exact theory and does not take into account the three‐dimensional shape of fibers and their material properties, comparative computations with an exact theory, the multiple multipole method (MMP), a variant of the generalized multipole technique, were performed. For small fiber diameters these simulations showed differences between diffraction patterns calculated via Fraunhofer theory and scattering patterns computed with MMP. The differences were strongly dependent on the optical properties of the fiber material.