Method and apparatus for particle concentration detection using a cloud chamber
US4967187A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 15, 1989 |
| Grant date | Oct 30, 1990 |
| Priority date | — |
| Expiry date | May 15, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG08B17/113
- WIPO fieldMeasurement
- WIPO sectorInstruments
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. The phototransistor measures the change in light intensity due to the concentration of the particles. A data storage device records each of the particle concentration levels sensed and measured in the zone so dangerous levels of gas concentrations can be …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.