The University of Missouri-Rolla cloud stimulation chamber is an expansion cloud chamber in which the interior walls are cooled by thermoelectric modules in synchronization with the cooling of the gas by expansion. To achieve the temperature uniformity required for the effective simulation of atomospheric processes the interior surface has been divided into 28 individually controlled areas. The chamber operating range extends from plus 40 degree to minus 40 degree C with cooling rates of up to 6 degree C/min in the upper two-thirds of the range
