BRUEL & KJAER VIBROCONTROL 8000 - 16.1.6 High Pass, Low Pass Corner Frequency; 16.1.7 Trip Multiply

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Brüel & Kjaer Vibro │ Instruction
VC-8000 MPS
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16.1.6 High Pass, Low Pass Corner Frequency
Measurements that show a high pass, and low pass
filter, apply a pre-filter first, and then determine the
measurements indicated. This pre-filter is applied to
these static measurements only – and not the
waveforms.
Filter setting restrictions:
• The low-pass filter corner should be no more
than 1000 x high-pass filter corner.
• If the low-pass and high-pass filters are too
close, there can be significant attenuation. The configuration software does not enforce filter
separation. As a guideline, maintain the filter separation shown in the table below.
Measurement Recommended Filter Separation
Radial Vibration
Shaft Absolute Radial Vibration
Low-Pass Corner > 10 x High-Pass Corner
Velocity
Acceleration
Low Frequency Acceleration
Low Frequency Velocity
Shaft Absolute Velocity
Low-Pass Corner > 2.5 x High-Pass Corner
Hydro Displacement
Hydro Velocity
Dynamic Pressure
Low-Pass Corner > 1.1 x High-Pass Corner
Aero Velocity (Tracking or Bandpass)
Aero Acceleration
Acceleration Enveloped
Low-Pass Corner > 1.3 x High-Pass Corner
Table 16-3) High-Pass and Low-Pass Filter Corner Separation
NOTE
High Pass, Low Pass does not apply to waveform data collection.
16.1.7 Trip Multiply
Trip Multiply (when enabled) increases the alarm set-points by the value specified. For example, a
Trip Multiply value of 2 will change the Alert alarm from 3 mils to 6 mils when Trip Multiply is enabled.
If Trip Multiply was 2.5, the Alert alarm would change from 3 mils to 7.5 mils.
The default value for Trip Multiply is 1. With a value of 1 the alarm will not change when trip multiply is
enabled (i.e. 3 mils x 1 = 3 mils)
Figure
16-3) High/Low Pass filters