Presenter Information

Deborah K. Bircher


Mechanical and Aerospace Engineering

Research Advisor

Alofs, Darryl J.

Advisor's Department

Mechanical and Aerospace Engineering

Funding Source

This work is sponsored by The University of Missouri-Rolla, OURE.


This paper concerns the performance testing of a system to collect and chemically analyze cloud condensation nuclei (CCN). These are the atmospheric particles which nucleate cloud drops.

The air is humidified by passage through the "haze chamber", consisting of parallel vertical plates that are covered with cotton cloth and are kept wet by water supplied at the top edge. The plates are adiabatic , and should equilibrate in temperature at the wet bulb temperature of the incoming air. Measurements of the plate temperature with eighty thermocouples indicate behavior consistent with theory.

Another part of the system is called the CFD (continuous flow diffusion chamber). This consists of isothermal parallel wet plates with two cold plates at 18 C and one hot plate at 2 3 C. The hot plate contains twelve electric heaters which can be individually adjusted to achieve an isothermal hot plate. Measurements of the hot plate temperatures with 40 thermocouples show that the plate was isothermal within an accuracy of 1 C.

Document Type


Presentation Date

29 Jan 1993


Cloud Physics