Project Title:

Development of an In Situ Particle Sizing System

08.13-0375
Development of an In Situ Particle Sizing System
SRS Technologies
555 Sparkman Drive, Suite 1406
Huntsville
AL
35805
Ghosh
Ashoke
18218
49,999
LaRC

Abstract:

The objective of this effort is to develop and examine the theoretical basis for
in situ particle sizing with a Laser Doppler Velocimeter-LDV optical system.  The
innovation of the proposed approach is the simultaneous measurement of four different
LDV signal characteristics to obtain simultaneously and in situ, particle size distributions,
particle number densities and particle velocities, for particles in the size range
O.25 to 1O pm.  The analysis will define ways to improve a particle sizing interferometer
(PSI) - which uses the LDV optical system and may use one or more beams of the LDV
- to measure accurately and simultaneously, particle size distributions, number densities
and velocities.  Improvement of the PSI will focus on simultaneously determining
particle size using four independent, synchronized measurements of the LDV signal.
 Comparison of the resulting particle size distributions from these four methods
will enable tighter tolerances to be specified on the measured size distributions.
 The analysis will also be utilized to:  (1)  determine measurement volume normalization
weightinq factors (2)  determine effects of particle index refraction variations,
(3)  develop a new inversion scheme which will define actual size distributions from
measured distributions, and (4)  identify size and scattering cross section.