- Author
-
Bricker, R. W.
- Title
- Test Results from a Comparative Evaluation of a Condensation Nuclei Fire Detector.
- Coporate
- Webb, Murray and Associates, Inc., Houston, TX
- Sponsor
- National Aeronautics and Space Administration, Washington, DC
- Report
-
NASA CR-3874,
March 1985,
62 p.
- Contract
- NAS9-15980
- Keywords
-
fire prevention
|
safety devices
|
photoelectric detectors
|
smoldering
|
plastics
|
ionization detectors
|
warning systems
|
alarm responses
- Identifiers
- detection systems
- Abstract
- A series of 138 tests was conducted to compare the fire/smoke alarm response of a Condensation Nuclei Fire Detector (CNFD) with photelectric and ionization detectors. Tests were conducted in a former control room 8.5 m (28 ft) by 8.9 m (29 ft 2 in) with a 2.7 m (9 ft) ceiling. The room had air supplied from above the ceiling and under the floor with return air exiting from ceiling grills. The environment was varied from 278 to 305 K (40 to 90 deg. F) and relative humidities from 8 to 65 percent. Four detection zones were located in the room. Each zone contained a sampling head for the CNFD, a photodetector, and an ionization detector so that each detector system had four opportunities to alarm during tests. The particle level in the test room was also monitored during tests with a condensation nuclei particle counter. The CNFD responded to 90 percent of exposures to smoldering plastic and 84 percent of exposures to visible fire. The photoelectric response was 43 and 12.5 percent respectively for the same conditions. The ionization response was 9 and 48 percent respectively.