| 摘要 |
<p>A fire detection system (10) includes a smoke detector (52) that measures smoke particle density indicative of smoldering fires and a CO2 detector (90) that measures CO2 concentration indicative of flaming fires. In a first operating current saving method, the smoke detector is operated at a normal PRF while the CO2 detector is operated at a very slow PRF. Smoke density measurements (14) produced by the smoke detector are compared with a set of tentative fire detection criteria (18, 20, 22, 14), and if met, the CO2 detector PRF is substantially increased to rapidly produce CO2 concentration measurements (26) that are compared to a set of conclusive fire detection criteria (30, 32, 36, 38). In a second operating current saving method, the CO2 detector is operated at a normal PRF while the smoke detector is operated at a zero PRF. CO2 concentration measurements produced by the CO2 detector are compared with a set of tentative fire detection criteria (30, 32, 36, 38), and if met, the smoke detector PRF is substantially increased to rapidly produce smoke density measurements that are compared to a set of conclusive fire detection criteria (18, 20, 22, 24). In a reliability improving operating method, electrical current draw and/or signal presence of the smoke and CO2 detectors are monitored to determine whether either detector has failed. If a failure is detected, fire detection criteria normally employed are changed to criteria optimized for the remaining detector.</p> |
