## What is vibration phase diagram?

The phase diagram or phase space is a geometric representation of the Hamiltonian function of a dynamic system. It represents the relationship between the potential and kinetic energies at any time.

**How the concept of phase angle is used in vibrations?**

When vibrating under the influence of a vibratory force, there is a phase angle between the displacement and the force for any given frequency in the spectrum. At resonance the phase angle between the displacement and applied force is either +90-degrees or -90-degrees.

### What does 1X vibration mean?

Vibration is any oscillatory motion caused by a restorative force. Free vibration occurs when a bell is rung or a guitar string is plucked. The most common vibration frequency is directly caused by this spinning shaft is dubbed fundamental shaft speed or running speed and is denoted as “1X vibration.”

**Which two vibration measures are 180 degrees out of phase?**

Destructive interference occurs when the maxima of two waves are 180 degrees out of phase: a positive displacement of one wave is cancelled exactly by a negative displacement of the other wave. The amplitude of the resulting wave is zero.

#### What is 1X 2X 3X vibration?

A 1X and 2X vibration signal predominant in the axial direction is generally the indicator of a misalignment between two coupled shafts. The spectrum shows high axial vibration at 1X plus some 2X and 3X with 180° phase difference across the coupling in the axial direction.

**What is phase angle vibration?**

Phase describes the relative timing between two signals. Phase is the angle difference between a measured point and a reference point. Phase is the angle difference measured from the peak of a vibration signal backward in time to the reference trigger point.

## What is phase angle of vibration?

Phase is the angle difference measured from the peak of a vibration signal backward in time to the reference trigger point. The following figure shows a phase of 90 degrees and the relationship between a vibration signal and reference signal. The peak of the vibration signal lags 90 degrees behind the trigger point.

**What is meant by phase angle?**

phase angle: Of a periodic wave, the number of suitable units of angular measure between a point on the wave and a reference point. Usually, at least one full cycle of each wave is plotted, with 360° (2 radians) encompassing one full cycle.

### What is FFT in vibration?

The fast Fourier transform (FFT) is an efficient algorithm used to compute a discrete Fourier transform (DFT). This Fourier transform outputs vibration amplitude as a function of frequency so that the analyzer can understand what is causing the vibration.

**How is the phase of a vibration measured?**

In vibration analysis, phase can be measured using either an absolute or relative reference. Most single channel vibration analyzers can measure absolute phase of a signal, relative to an absolute reference such as a tachometer pulse.

#### How is phase lag related to time constants?

As the figure indicates, the response is slow (the large time constants were an early indication of this behavior), with a peak response slightly larger than 1.2 after approximately 20 s and a steady-state response reached after 90 s. The phase-lag compensator has a negative phase angle and so is used to subtract phase from an uncompensated system.

**How does phase lag affect the P + I controller?**

This compensator improves the static error of the feedback system, similarly to the P + I controller. The lag compensator limits the low-frequency amplification (gain) of the P + I controller, which produces a minimal effect on the transient response, particularly when the zero-pole couple is close to the origin.

## How does phase lag improve the stability of a feedback system?

Phase-lag compensation can improve/realize the stability of an existing feedback system by reducing the high-frequency gain to a negative value from a positive value, at a phase angle of −180°.