Masters Theses


"This thesis describes the design, construction, and application of an analog control system for the temperature control of an expansion cloud chamber. During the expansion, the sample gas and the chamber walls are cooled at the same rate so as to maintain adiabaticity. The control system measures the wall temperature with transistor temperature sensors, calculates the gas temperature from the gas pressure using the adiabatic gas law, and generates a control signal proportional to their difference. The control precision is sufficient to allow the chamber to be used in the study of atmospheric phenomena.

The chamber is a ten-sided right prism, 61 centimeters high and 48 centimeters in diameter. It has a sensitive volume of 0.11 meters cubed and an inner wall surface of 1.3 meters squared which is cooled by 844 thermoelectric units imbedded between the inner wall and heat sink. The heat sink is thermostated by liquid coolant that carries away the heat transferred out of the chamber by the thermoelectric units. The maximum power transfer is 40 kilowatts and the maximum rate of cooling is 1.3 °C per second. The preliminary experiments, however, will be run at a rate of 0.005°C per second. The large amount of thermoelectrics are needed to decrease the temperature gradient on the chamber's inner walls. The large amount of power will be needed for later, more dynamic atmospheric phenomena.

Since the primary objective of the Cloud Simulation Chamber is to have adiabatic expansions, the gas temperature and the wall temperature must be the same. Special efforts were made to control these temperatures within the allowable difference of a few millidegrees Kelvin for the expected expansion.

It is hoped that this thesis will serve as a reference which will insure the future continuity of the Cloud Simulation Chamber"--Abstract, pages ii-iii.


Dillman, Norman G., 1938-2010

Committee Member(s)

Kassner, James L.
Hagen, Donald E.


Electrical and Computer Engineering

Degree Name

M.S. in Electrical Engineering


United States. Naval Air Systems Command
United States. Office of Naval Research


All of the work was financially supported by the Naval Air Systems Command and the Office of Naval Research, grant number N00014-69-A-0141-000S and the Atmospheric Sciences Section of the National Science Foundation, grant number GA-36041.


University of Missouri--Rolla

Publication Date



viii, 51 pages

Note about bibliography

Includes bibliographical references (page 50).


© 1973 Andrew C. Tebelak, All rights reserved.

Document Type

Thesis - Open Access

File Type




Subject Headings

Cloud chamber
Cloud physics -- Experiments
Temperature control -- Equipment and supplies -- Design

Thesis Number

T 2928

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