Infrasound generating device based on a displacement-feedback type vibration exciter

Abstract

The infrasound generating device based on a displacement-feedback type vibration exciter comprises a displacement-feedback type vibration exciter system, an infrasound generating chamber () and a laser vibrometer (); the displacement feedback mechanism is adopted in the vibration exciter (). The piston () is driven by the vibration exciter to move in a sinusoidal manner in the cavity () of the airtight infrasound generating chamber () and the standard infrasonic pressure signal with low harmonic distortion can be achieved. The displacement of the moving part () of the vibration exciter () can be measured by the laser vibrometer () through the measurement beam () injecting into the vibration exciter () through the optical channel running through the vibration exciter and the standard infrasonic pressure can also be obtained. The value of the standard sound pressure produced by the infrasound generating chamber is calculated. Such value is used as the calibration reference for the infrasound sensors () to be calibrated in order to achieve the primary calibration of the infrasound sensors. The standard infrasonic sensor can be installed inside the infrasound generating chamber () and the output of the standard infrasonic sensor can be used as the reference for the infrasonic sensor () to be calibrated in order to achieve the secondary calibration of the infrasound sensors. This invention has the advantages of technical maturity, high feasibility, easy to realize, high calibration accuracy and so on.