Honda G100K2 Applications Manual page 30

VIBRATION ACCELERATION
Acceleration means an amount of change in velocity within a specific period of time (cm/s², m/s²).
INDICATION CHARACTERISTICS OF VIBRATION METERS
A vibration is expressed by the amplitude, vibration speed and vibration acceleration.
Vibrations in machines are most often discussed in terms of their vibration acceleration, which is indicated by units
G and dB.
PEAK
The peak is used for measuring impulsive vibrations and directly follows the peak value of the waveform.
Therefore a peak represents the value at the top (half amplitude) of the wave.
EQ PEAK (EQUIVALENT PEAK)
The equivalent peak is the peak value obtained when the actual waveform is corrected as a sinusoidal vibration.
It is used commonly when discussing vibrations in automobiles and engines.
RMS (ROOT MEANS SQUARE)
The RMS is the Root Means Square, and is equal to 1 /
LOW PASS FILTER
The important features of vibration are the level (measured in terms of velocity or acceleration) and the frequency at
which the vibration occurs; the closer vibration occurs to the natural or resonant frequency, the greater the effect will
be.
The natural frequency of engines running at maximum speeds of 10 000 rpm is below the 200 Hz level; therefore
high frequency vibration measurement is not used for vibration analysis.
For vibration measurement on engine driven applications, a 500 Hz low pass filter should be used to filter out the
influence of high frequency vibration.
"G" is a unit of vibration acceleration based on
gravitational acceleration.
980 cm/s² = 9.8 m/s² = 1G
2 of the equivalent peak.
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VIBRATION