| 摘要 |
PURPOSE:To economically monitor a wide area by a small number of smoke sensors by generating a light pulse train signal which includes address information on an abnormality occurrence area when an optical signal transmission line is cut off owing to the abnormality occurrence of smoke emission. CONSTITUTION:A projector 1-1 in a monitoring area A emits a single infrared- ray pulse at all times by mode switching. A light receiver 2-1 which receives the pulse inputs a single DC pulse corresponding to the output to the projector in a following monitor area and thus the output of a final light receiver is inputted to a center monitoring device 3 by successive relaying. If the single pulse is cut off by smoke, etc., the projector in a following area adjacent to a monitoring area where the smoke is emitted sends an infrared-ray light pulse train together with added address information on the monitoring area where the smoke is emitted. The pulse train is relayed by following light receivers and projectors and the output of the final light receiver is inputted to the device 3, which displays and indicates the address of the monitoring area where the smoke is emitted by detecting the address information.
|
