Design and Experimental Study of Bellows Type Standard Infrasound Generator

Abstract

Infrasound is widely used in nature and human activities, such as earthquakes, volcanic eruptions, mudslides, nuclear explosions, supersonic flight, weapons targeting, etc. Infrasound has strong penetrating ability, long propagation distance, low attenuation, and is widely used in environmental monitoring, military fields, industrial production and other fields. The monitoring of infrasound sound pressure signal mainly depends on the infrasound sensor, and the accurate measurement of infrasound sound pressure mainly depends on the calibration of the infrasound sensor, and the accurate measurement of the infrasound sensor is the premise and guarantee of the application of the infrasound sensor. In this paper, we propose a bellows type standard infrasound generator solution for the piston leakage problem of the most widely used gas cavity pressure method in the calibration of infrasound sensors, obtain the expression of sound field distribution in the bellows by theoretical derivation, and design a calibration device containing an infrasound sound pressure generator, feedback control and infrasound excitation system, data acquisition conditioning system and laser measurement calculation system. The above device was physically built and experiments were conducted on the bellows type standard infrasound generator, and the infrasound time-domain waveform maps from 0.01Hz to 20Hz were obtained. The experimental results show that the bellows type standard infrasound generator designed in this paper can generate standard infrasound sound pressure signals.