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

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)

Document Details

Document Type
Technical Report
Publication Date
Mar 01, 1970
Accession Number
AD0702755

Entities

People

  • Hratch Semerjian
  • John E. Cole Iii
  • Richard A. Dobbins

Organizations

  • Brown University

Tags

DTIC Thesaurus Topics

  • Calibration
  • Chambers
  • Cloud Chambers
  • Coefficients
  • Communication Equipment
  • Condensation
  • Electronic Equipment
  • Measurement
  • Measuring Instruments
  • Mie Scattering
  • Oscillation
  • Oscillators
  • Scattering

Fields of Study

  • Environmental science

Readers

  • Aerosol Science/Aerosol Physics
  • Theoretical Analysis.

Technology Areas

  • Microelectronics