| 摘要 |
<p>A fire alarm system includes a receiver (1) adapted to detect the presence of a fire on the basis of analog detection data contained in a received signal which is connected by means of a transmission line (2) to a plurality of analog type sensors (3), each of which is arranged in a respective monitoring area monitored by the receiver and is adapted to produce analog detection data representative of the value of a parameter, or a change thereof, caused by a fire and to transmit the data to the receiver. Associated with each analog type sensor (3) is a plurality of on-off type sensors (7) which are arranged in the same monitoring area as the associated analog type sensor, are adapted to be switched to produce a fire signal when the change in the said parameter exceeds a predetermined threshold value and are connected to a common signal line (6) connected to the associated analog type sensor (3).</p> |
