Automatic Calibration Method and System for Microphone Sensitivity of Power Equipment Noise Collection Device

Abstract

The invention discloses a method and system for automatically calibrating the microphone sensitivity of a noise collection device for power equipment. The method of the invention includes collecting an AC voltage signal at the outlet of a microphone preamplifier; performing Fourier transform on the AC voltage signal to obtain a signal spectrum; judging the signal spectrum Whether the main frequency is the first preset frequency, and the ratio of the frequency component energy of the first preset frequency in the spectrum to the energy sum of each frequency component in the range of the second preset frequency is greater than the preset threshold, and if it is true, it is judged When is the microphone sensitivity calibration working state, the effective value of the AC voltage signal at the outlet of the microphone preamplifier is the latest sensitivity of the microphone. The invention does not need to artificially set the sensitivity of the microphone, is suitable for the automatic calibration of the microphone of the noise collection device of the electric equipment, can reduce the workload of the noise detection personnel, and improves the noise collection efficiency.

Description

technical field [0001] The invention relates to the noise detection technology of electric power equipment, in particular to a method and system for automatically calibrating the sensitivity of a microphone of a noise collection device for electric power equipment. Background technique [0002] Power equipment noise collection devices generally include microphones, preamplifiers, and main controllers. Among them, the microphone uses a thin film to detect the sound wave signal and convert it into an electrical signal, the preamplifier is mainly used for impedance conversion, and the main controller is used for acquisition control, A / D conversion and sound pressure level calculation. [0003] Since the air temperature, humidity and other environmental conditions around the power equipment often change, which will affect the sensitivity of the microphone diaphragm, in order to ensure the accuracy of the noise measurement results, the power equipment noise collection device need...

AI Technical Summary

Problems solved by technology

Usually, an acoustic calibrator is used to calibrate it, and the noise collection device of power equipment starts the calibration function, and the detection personnel adjust the sensitivity of the device, which has the problems of heavy calibration workload and low noise collection efficiency, especially for large-scale noise collection devices , the above problems are more prominent

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