When performing vibration measurements during route-based maintenance activities, different vibration measurements uncover different issues with plant machinery.

In this 4:20 YouTube video, PeakVue Analysis, Emerson’s Mark Granger demonstrates some of these differences in vibration analysis using a spring-mass assembly.

Mark connects a triaxial accelerometer or triax to the spring mass and shows the differences in vibration signals when views from the CSI 2140 portable vibration analyzer.

Mark oscillates the mass and records the vibration readings coming in from the triax to the CSI 2140. These readings include PeakVue, acceleration, and velocity. The velocity measurement displays the speed of the mass and is as expected—a sinusoidal waveform.

https://www.youtube.com/watch?v=IAY60Dzg6hE

He next shows the acceleration plot. Acceleration refers to the force on the machine. The plot displays the sinusoidal wave with spikes superimposed. The spikes are caused by the spring rubbing against the mass during the oscillations.

The third property Mark showed is impact, which is the force that is being applied on a period or non-periodic basis. The PeakVue analysis detects impact by measuring G-force levels at over 100,000 vibration readings per second.

Mark then compares the PeakVue analysis with another signal processing technique called demodulation. Demodulation data will strip away the sinusoidal energy information, but it does not get the absolute accurate peak level of the impacts.

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