TIME-RESOLVED MEASUREMENT OF DROPLET SIZE AND CONCENTRATION IN CLOUD CHAMBERS,

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Abstract:

An optical method for measuring droplet size and concentration in a cloud chamber on a time-resolved basis is discussed. During the growth of the droplets optical transmission is continuously measured by high speed electronic equipment at two wavelengths. Interpretation of the resulting transmission versus time curves is made on the basis of Mie scattering theory. The appearance of oscillatory regions in the transmission curves is related to the primary oscillations of the scattering coefficient and indicates the presence of a monodisperse cloud. Two methods of data interpretation are discussed from which absolute values of droplet size and concentration are obtained. The technique is applicable to condensation studies conducted in Wilsen cloud chambers. It is suggested that apparatus of the type described is also suitable for the absolute calibration of condensation-nuclei counters of various types. Author

Author(s):
Cole, John E., Iii ; Dobbins, Richard A. ; Semerjian, Hratch
Author Organization(s):
BROWN UNIV PROVIDENCE R I DIV OF ENGINEERING
Pagination:
0028

Security Markings

DOCUMENT & CONTEXTUAL SUMMARY

Distribution:
Approved For Public Release

RECORD

Collection: TR
Identifying Numbers
Contract/Grant Number(s):
N00014-67-A-0191-0001
 Subject Terms
Joint Capability Areas:
JCA_6.1_Information Transport; JCA_6_Net Centric
Communities of Interest:
No COI(s) Identified
Descriptor(s):
(*CLOUD CHAMBERS, *PARTICLE SIZE), CALIBRATION, CONCENTRATION(CHEMISTRY), NUCLEATION, LIGHT TRANSMISSION, FOG
Field(s)/Group(s):
Meteorology, Nuclear Instrumentation
Keyword(s):
MIE SCATTERING, *CONDENSATION NUCLEI
Report Date:
1970 Mar 01