Aerosol grain size sensing method based on dual-wavelength scattered signals and application of method to fire smoke detection

Abstract

The invention relates to an aerosol grain size sensing method based on dual-wavelength scattered signals and an application of the method to fire smoke detection, and belongs to the technical field of fire alarms. The method comprises steps as follows: calculating the ratio R of the blue light scattered power to the infrared light scattered power after receiving corresponding scattered signals reflected by aerosol with the blue light scattered power PBL and the infrared light scattered power PIR; determining the median grain size dmed according to the relation between the ratio R of the blue light scattered power to the infrared light scattered power and the median grain size dmed of aerosol; comparing the blue light scattered power PBL and the infrared light scattered power PIR with set corresponding thresholds PBLth and PIRth, and sending corresponding interference prompt signals or corresponding firm alarm signals. With the adoption of the method, fire type alarm signals can be judged and sent, so that targeted reasonable measures can be taken, and meanwhile, false alarms caused by aerosol under non-fire conditions can be avoided.

Description

technical field [0001] The invention relates to an aerosol detection and sensing method, in particular to an aerosol particle size sensing method based on dual-wavelength scattering signals, and also relates to the application of the method in fire smoke detection, belonging to the technical field of fire alarming. Background technique [0002] The smoke and fire detection technology based on the principle of aerosol light scattering has been widely used since it came out in the 1970s, but the existing technology cannot perceive the size of aerosol particles, and cannot distinguish fire smoke from dust and water vapor, so false alarms become a problem. The biggest problem with probing effectiveness. [0003] Generally, the particle size of fire aerosols produced by material combustion is less than 1 μm, and the particle size of non-fire aerosols such as water vapor and dust is greater than 1 μm. [0004] Patent Nos. 200410031104.5 and 201180039383.8 both disclose the method...

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Problems solved by technology

[0005] However, the above existing methods can only detect and judge whether the particle size of the aerosol is larger or smaller than the limit of 1 μm, but cannot "perceive" its specific particle size. Therefore, it is difficult to judge the nature of the fire based on the characteristics of the aerosol to take effective measures. targeted measures

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