Buzz-o-sonic: Movies
Training videos for our special low cost system for refractories1
Impulse Excitation
Out-of-plane Flexure
1the microphone and supports used in these videos are not part of our standard system that uses special certified microphones/signal conditioners/self-calibrating DAQ cards and anodized aluminum sample supports
When applying the impulse excitation technique using the Buzz-o-sonic testing system, supports can be dispensed with in some cases if damping is not being measured. In these cases the sample is simply laid down on a pad of soft polyurethane foam. The change in frequency due to increased external damping is usually negligible and can be tested for. Below is an example of a disc being tested in such a manner.
Testing a ceramic disc
Below is an example of another disc being tested. However, this disc vibrates such that the overtones are also excited along with the fundamental. Although the fundamental frequency is easily identified in the power spectrum of Buzz-o-sonic, the waveform can be offset in time so that only the fundamental is left vibrating (the overtones decay more rapidly because their frequencies are higher (logarithmic decrement of the amplitude)).
Eliminating overtones from the power spectrum in Buzz-o-sonic