BETAVIB Overall Quantities Explained

BETAVIB Overall Quantities Explained

Following is an explanation of the 5 overall quantities which come standard in all measurements

VELOCITY

The Betavib “Velocity” value is an RMS value which is an averaged value extracted from a velocity spectrum.

The spectrum from which the RMS Velocity is extracted from is created using the following parameters:

1. Fmin – Fmax: 10Hz – 1kHz

2. 4 avgs @ 70% overlap

3. Hanning window

PEAK

The Betavib “PEAK” value is an acceleration value expressed in gs and is calculated from the long time waveform. It is determined by the equation:

(the highest positive going peak) + (the absolute value of the lowest negative going peak) ÷ 2

RMS

The BetaVib “RMS” value is the overall RMS acceleration value of the long time waveform.

KU

The BetaVib Kurtosis value is a measure of vibration impulsiveness. It is calculated from the long time waveform and is the 4th order quadratic moment, expressed in the equation:

CF

The BetaVib Crest Factor value is taken from the long time waveform and is the ratio of the peak value to the RMS value.

The peak value is determined by averaging together the highest positive going peak with the absolute value of the lowest negative going peak.