Abstract: A device consisting of a monolithic block of material that is used as a housing of an apparatus for determining the density, or changes in density, of small particles, that contains an elongated chamber formed within the block that serves as a cloud chamber, and a trough formed in said block and defining a humidification chamber. The block includes passageways that connect the cloud chamber to the humidification chamber and inlet and exhaust passageways, as well as providing mountings for various valves, such as a humidity valve, by-pass valve, and vacuum valve used in the apparatus.
Abstract: Method and apparatus for sampling the gaseous medium of a zone or area to determine the concentration, or changes in concentration, of submicron particles suspended in the gaseous medium of that area or zone using an elongated cloud chamber. A light source and a phototransistor are disposed in the cloud chamber and spaced apart so as to be electronically responsive to varying levels of light. A microprocessor is connected to a programmable memory EPROM and has pre-programmed data instructions on particle concentration levels. The EPROM sequences the microprocessor to operate the valves that sequentially sample the gaseous medium in the cloud chamber, and opens the exhaust valve in the cloud chamber to create a condition of reduced gas pressure therein. The sample of gaseous medium containing submicron particles then precipitates or condenses a portion of the cloud in the chamber in proportion to the concentration of the particles.
Type:
Grant
Filed:
May 15, 1989
Date of Patent:
October 30, 1990
Assignee:
Research Equipment Corporation
Inventors:
Jerome E. Dumas, Eric W. Harris, Jr., John G. MacDougal