Contents
What is the phase of vibrations?
any part of the path described by a particle or body in making a complete vibration, in distinction from other parts, as while moving from one extreme to the other, or on one side of the line of rest, in distinction from the opposite.
How does a vibrating machine generate vibration signals amplitude vs time plot?
An accelerometer attached to the machine generates a voltage signal that corresponds to the amount of vibration and the frequency of vibration the machine is producing, usually how many times per second or minute the vibration occurs. time (known as time waveform), amplitude vs.
What is out of phase in vibration?
In Figure 1, the sine waves (vibrations) of Machines A and B do not reach their positive peaks at the same time (i.e., when Machine A reaches the top of the peak, Machine B is at the bottom). This is an indication that they are “out of phase.”
How are phase measurements used in vibration analysis?
Engine tuning using a timing light is phase analysis. A phase study is a collection of phase measurements made on a machine or structure and evaluated to reveal information about relative motion between components. In vibration analysis, phase is measured using absolute or relative techniques.
How are accelerometers used to measure high frequency vibration?
Figure 1. Accelerometers are versatile sensors used for high or low frequency vibration as well as shock measurements. Another sensor you can use to measure vibration is the proximity probe. Unlike accelerometers, which measure acceleration to determine vibration, proximity probes are noncontacting transducers that measure distance to a target.
When to use fast Fourier transform in vibration analysis?
Fast Fourier transform is most often used for detecting machine faults like misalignment or unbalance. Phase measurement: When talking about vibration analysis, phase is a relative time difference between two signals measured in units of angle as opposed to time. It only works if the two signals being compared are of the same frequency.
When to use phase analysis on problem machines?
When to use Phase Analysis. Everyone needs phase analysis. A phase study should be made on problem machines when the source of the vibration is not clear or when it is necessary to confirm suspected sources of vibration.