Patent ID: 11935381
Assignee: NEC CORPORATION
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 4:
5. A fire detection method comprising:
transmitting, by one or more sensors installed in an optical fiber, first information indicating a location in the optical fiber when detecting that vibration occurred at the location;
detecting, by each of a plurality of gas state detectors, a first concentration of a first gas and a second concentration of a second gas at a corresponding monitored location, and when a pattern of changes in a ratio of the first concentration to the second concentration at the corresponding monitored location matches a predetermined pattern, transmitting second information that the pattern of changes matches the predetermined pattern and third information indicating the corresponding monitored location; and
receiving, by a computer, the first, second, and third information, and outputting fourth information indicating a sign of a fire outbreak occurred at the location when the location indicated by the received first information is within the corresponding monitored location indicated by the received third information.