Vibration level of the pump
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Can the vibration level of a pump be determined solely based on the velocity amplitude in mm/s? Can displacement amplitude in mm or acceleration amplitude in mm/s2 be used instead? As long as there is no way to convert between these values, are there any other methods that can be used to determine it?
Vibration is expressed in displacement, velocity, and acceleration, all of which have different units; how to convert between them? Just like how length is converted to speed. Both speed and acceleration are functions of time. Displacement has no relation to time.
There are two methods for evaluating the vibration mode of rotating machinery: 1 – Using bearing vibration values； 2-Utilize the shaft vibration value. The vibration of the pump mentioned by the original poster is generally measured using the first method, that is, the bearing vibration value. For the assessment of bearing vibration, the double amplitude of displacement was commonly used in the past, but in recent years, vibration intensity has gradually been adopted as a measurement method; vibration intensity refers to the effective value of the vibration velocity. As the three parameters of vibration, vibration displacement, vibration velocity, and vibration acceleration can be converted into one another. Since the vibration displacement is a function of time, taking the first derivative of the displacement signal with respect to time gives the vibration velocity, while taking the second derivative gives the vibration acceleration. Conversely, integrating the vibration acceleration signal once and twice yields the vibration velocity and vibration displacement.
Of course it can be converted; otherwise, how would a vibration meter have three parameters?
The velocity, displacement, and acceleration of vibration can be converted into one another
There was a post on the forum about mutual conversion; search for it yourself. However, only a rough conversion is possible, as the actual vibrations are not necessarily of a single frequency. Whether to use displacement or velocity depends solely on your criteria. Generally, it’s fine.