Methods for measuring velocity of vibration of surfaces without contact are currently very expensive. From the basics of technical acoustics it is theoretically possible to measure vibrations with sound pressure. So, we wonder whether vibrations can be measured with a microphone, which is a much cheaper choice than, for example, a laser vibrometer.
We measured acoustic pressure with a microphone and velocity of vibrations with a laser vibrometer. We are interested in the connection between these two and the effects of the frequency and the power of the source.
From the measurements we then found that sound pressure and velocity of vibrations are linearly dependent. The linear coefficient connecting soud pressure and velocity of vibrations increases linearly by increasing the frequency. Power of the source does not affect the coefficient. We have also learned that when measuring, we need to be aware of the size of chosen vibrating source and its properties. Sound pressure is an indicator of vibrations and is suitable for measuring the velocity and analisys of surface vibrations.
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