| 摘要 |
In a fire detection system, detectors of different sensitivities are arranged in pairs and the pairs of fire detectors are positioned at regular intervals along an elongated protection area, whereby detectors of one sensitivity alternating with detectors of the other sensitivity are connected via two line systems to a signal center which emits an alarm signal when an alarm signal is simultaneously received via both line systems. In use, for example in a vehicle tunnel, a more uniform response sensitivity is obtained along the protection area, accompanied by a decrease in the necessary number of fire detectors and a reduced tendency to false alarms. |
