Abstract: A fire alarm system, sensor and method for determining a fire by detecting a change in a temperature, smoke density and/or gas concentration due to a fire. The detection data values of the respective analog sensors are corrected based on areas of supervisory regions of the respective analog sensors which are defined by walls, beams or inwardly extending projections surrounding the respective analog sensors, and/or heights from the floor of the respective analog sensors. The fire determination is carried out based on the corrected data.

Abstract: An extinct type detector which detects and determines a concentration or density of a gas or vapor in a space on the basis of an attenuation of light due to the gas or vapor present within the space.The detector of this feature of the invention operates in such a way that the light emitting device is periodically driven to effect light emission, the first and the second photodetector devices receive the light from said light emitting device, the first and second storage means corresponding to the first and the second photodetector devices, respectively, cumulatively store the outputs from the respective photodetector devices, a difference in cumulative storage values between the first and the second storage means is detected to determine a concentration and density of the gas or vapor within the detecting space based on the detected difference.

Abstract: A fire alarm system which makes fire determination based on a novel idea which considers various changes of the physical phenomena in the surroundings caused in relation with the occurrence of a fire in terms of changes of vectors. These changes in the physical phenomena are detected by the detecting section in the form of analog data and processed by a data sampling section as sampled data and stored in a storing section in such a manner as discriminating them by the detecting sections. The tendencies of the changes are computed in a first computing section and the vectors representing the present or future conditions of the physical phenomena are computed from the sampled data. The vector is compared in a comparing section with a preliminarily set data related to the fire detection and when the relation therebetween is not a predetermined one, an alarm is given through an alarming section.

Abstract: An analog fire detector which comprises sensor means for detecting, in analog form, one or more kinds of quantity of state which change due to fire; a sampling means for sampling the detection outputs from the sensor means with a predetermined period; and fire determining means which predicts future fire data changes from the sampling data and generates a fire determination output signal when the prediction data satisfies predetermined fire conditions.

Abstract: A process for detecting a change in the physical phenomena caused by a fire in an analog form, periodically sampling the analog detection data, calculating moving average values of the time series sampling data for filtering, and establishing the sampling period and the number of smoothing data provided for the moving average calculation so that a cut-off frequency of the filtering is established which is coincident with the maximum frequency of the main frequency components of the analog detection data. The invention also relates to a fire detector and a fire alarm system for carrying out such a process.

Abstract: A light-attenuation type fire detector assembly of the present invention comprises a light emission drive section including a light emitter for radiating light having an intensity corresponding to an input signal level; a smoke detecting section including a light receiver which directly receives the light radiated from the light emission drive section and is adapted to output a detection signal corresponding to the received light amount of the light receiver; a smoke amount computing section for computing the amount of smoke based on the detection signal from the smoke detecting section; a delay circuit for retarding input of the detection signal from the smoke detecting section to the light emission drive section for a predetermined time; and a control section for repeating the operations of the light emission drive section, the smoke detecting section and the delay circuit and generating a control signal after a predetermined period of time has been passed or a predetermined times of operation has been done