Condensation Method for Humidity Measurement in the UMR Cloud Simulation Chamber

Abstract

A cloud simulation facility has been developed for the study of various atmospheric cloud processes. The initial relative humidity of the air sample put into the cloud chamber is a key parameter in virtually any experiment and needs to be known accurately. This report describes how the cloud simulation chamber itself has been used as a condensation type hygrometer to calibrate the system's humidifier. Two distinct and physically different methods for inferring mixing ratio are used, one exploiting the sensitivity of aerosol activation to humidity, and the other exploiting the sensitivity of the rate of growth of cloud droplets to humidity. The two methods give agreement with each other to within a precision of one part per thousand in mixing ratio.

Department(s)

Physics

Second Department

Mechanical and Aerospace Engineering

Keywords and Phrases

Atmospheric Humidity--Measurements; Meteorology--Clouds; Water--Vaporization

International Standard Serial Number (ISSN)

0160-1741

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 1988 National Institute of Standards and Technology (NIST), All rights reserved.

Publication Date

01 Jul 1988

Link to Full Text

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