Accession Number : AD0608374

Title :   INSTRUMENTATION FOR THE DIRECT MEASUREMENT OF FOG DROPLET GROWTH.

Descriptive Note : Final rept.,

Corporate Author : BOLLAY (E) ASSOCIATES INC SANTA BARBARA CALIF

Personal Author(s) : BEGUN,Robert A.

Report Date : AUG 1964

Pagination or Media Count : 144

Abstract : An instrument is in operation that directly measures water droplet growth as a precursor of developmental fog formation. Its potential was recognized as a result of the mesoscale prediction work being done by our company in support of ATC operations at high density air terminals. Water droplet sizes of interest range from 0.1 to 1.0 microns, prior to the particles becoming visible to the human eye. Using optical techniques, the instrument measures the transmission of two discrete wavelengths of ultraviolet light over a path length of 125 feet. The atmosphere is not disturbed. As the absolute value of the transmission is not quantitatively measured, the alignment of the unit is not critical. Several cases of developmental fog were successfully indicated by the instrument several hours before visibility was affected. (Author)

Descriptors :   (*METEOROLOGICAL INSTRUMENTS, FOG), (*FOG, METEOROLOGICAL INSTRUMENTS), OPTICAL EQUIPMENT, ULTRAVIOLET RADIATION, WEATHER FORECASTING, WATER, DROPS, GROWTH(PHYSIOLOGY), MEASURING INSTRUMENTS

Distribution Statement : APPROVED FOR PUBLIC RELEASE