Accession Number:

ADA277179

Title:

Backscatter and Transmission of Aerosol at UV through Middle IR wavelengths

Descriptive Note:

Interim rept. no. 4, Jan-Sep 1993

Corporate Author:

UNIVERSITY COLL GALWAY (IRELAND)

Personal Author(s):

Report Date:

1993-12-21

Pagination or Media Count:

16.0

Abstract:

Simultaneous measurements of backscatter and transmission coefficients, sigma b and sigma e for obscuring and biological aerosols using a NdYag pulsed laser system at 1064, 532, and 266 nm wavelengths are being investigated in the laboratory. Forward scattering measurements are obtained at wavelengths 1064 and 532 nm for water droplet polydispersions and compares favourably with theoretical values for relatively narrow size distributions. However, for broader size distribution, the contribution by forward scattered radiation to the estimation signal is significant and needs to be accounted for in extinction and backscatter measurements. The aerosol chamber for obscuring carbon powder aerosol is described. Measurements of pollen and spore biological aerosol using an array of passive Tauber traps are presented. Percentage counts as well as species concentration values are given for seven sites in the west of Ireland covering the period from November 1992 through May 1993. Backscatter, Transmission, Biological aerosol, Spore, Pollen.

Subject Categories:

  • Biology
  • Physical Chemistry
  • Lasers and Masers
  • Chemical, Biological and Radiological Warfare

Distribution Statement:

APPROVED FOR PUBLIC RELEASE