A Porous Metal Composite Structure Array Electret Noise Detector

Abstract

The invention provides a noise detector for porous metal composite arrayed electrets. According to the feature that a great amount of communicated voids exist in a porous metal material composite structure, when sound wave propagates in the material, sound energy under certain frequency is continuously consumed by air glutinousness and thermal conduction of the material; the sounds under different frequencies are treated in a classified manner; accordingly, interference of various stray waves is effectively reduced. One of two sets of synchronous sound acquisition sensors in the same type is packaged and isolated from external high-frequency signals and serves as low-frequency background noise for monitoring signals, the sensors are alternately arranged at intervals in an array manner, acquired signals are fused and filtered in a controller and are subjected to background subtraction with low-frequency signals acquired other ways around a sampling point, the low-frequency background noise is deducted by spectrum transformation, and the direction of a noise source is judged according to the intensity and phase change of signals acquired by arrayed noise monitors mounted in different directions.

Description

technical field [0001] The invention relates to a noise detector, in particular to a porous metal composite structure array electret noise detector, which belongs to the technical field of environmental monitoring and environmental protection. Background technique [0002] With the rapid development of the country's economic construction, people are paying more and more attention to the problem of environmental pollution related to noise. Although noise pollution is different from other environmental pollution, it is invisible and intangible, but its impact on human beings is all-round, not only affecting people's normal work and life, but also causing interference and damage to the natural environment. endanger people's health. [0003] The commonly used sound sensors are divided into moving coil type, capacitive type, piezoelectric type, aluminum strip type, carbon particle type and semiconductor type, etc. Among them, the capacitive electret microphone has high reliabili...

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Problems solved by technology

[0005] In order to overcome the disadvantages of low sensitivity in measuring high-frequency noise in the low-frequency noise environment of the prior art and the inability to accurately judge the noise direction, the present invention provides a porous metal composite structure array electret noise detector. The interior contains a large number of connected gaps, so that when the sound wave enters the material, the sound energy of a specific frequency band is continuously lost through the viscosity of the air and the thermal conductivity of the material, thus achieving the effect of grading the sound of different frequency bands. Effectively reduce all kinds of clutter interference generated when signals of different frequency bands and signals are mixed, by encapsulating one of the two sets of microphones of the same model that simultaneously collects sound signals and isolating them from external high-frequency signals, it is used as the low-frequency background noise of the monitoring signal, and Carry out array-style staggered arrangement at equal intervals, perform fusion filtering on the collected signals in the controller, and calculate the background difference with the low-frequency signals collected by other channels around the sampling point, use spectrum transformation to reduce low-frequency background noise, and according to the installation Based on the signal strength and phase changes collected by array noise monitors in different directions, the location of the noise source can be judged, which solves the technical defect that it is difficult to accurately measure the high-frequency noise pollution and the location of the high-frequency noise pollution source in a low-frequency noise environment

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