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Y Measure Unit: unit of measurement used on y axis (m/s
2
; g);
X Measure Unit: unit of measurement used on x axis (Hz; rpm);
dB Ref Value: reference value setting to calculate decibels for the display with scale type dB on
Y axis.
3.5.3.2 Overall measurement
Opening a new FFT view the three axes Overall indication appears on the upper right side of the
window.
The Overall is an algorithm able to evaluate, inside a well-defined bandwith, the vibration total
value; this computation shows an idea of the total vibration effect but doesn't offer an evaluation of
the magnitude distribution at the single frequency component.
Once the bandwidth is defined (between MinX(Hz) and MaxX(Hz)) the Overall is computed
according to the following formula
∑
=
=
n
i
i
A
Overall
0
2
Where n is the total rows number in the defined bandwidth and Ai is the amplitude of each row of
all the rows in the vibration spectra in the same bandwidth.
3.5.4 Triggered: event synchronized measures
The TRIGGERED mode enables the synchronization of data acquisition with vibrational events
whose characteristics have been set by the user (called trigger levels or thresholds) for an
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