Specifications

Reference Manual
MHM-97408, Rev. 2
June 2008
C-3
CSI 9420
PEAKVUE PeakVue is a patented technique that is extremely useful for isolating
high-frequency phenomena associated with developing faults, especially in
rolling-element bearings.
The premise for PeakVue is that the high-frequency components are not
readily detected with more conventional measurements such as overall
velocity, low-frequency energy (LFE), or digital overall. This is because the
low-frequency measurements either average the energy or provide an energy
summation over a relatively large frequency band and the relative amount of
energy that is typically contributed by the high-frequency components is quite
small. As a result, even large "spikes" are difficult to detect with classic
techniques.
The difference in the vibration waveform and the associated measurement for
Overall Vibration versus PeakVue is depicted conceptually in the illustrations
below. Overall Vibration provides an indication of the total low-frequency
energy in the waveform. PeakVue, on the other hand, provides an indication
of the maximum excursion in the waveform, which is how indications of many
developing bearing faults are first manifested.
The PeakVue algorithm isolates the peak energy of interest to provide early
indications of developing bearing faults such as inner and outer race defects,
ball defects, and lubrication problems. Any type of "impacting" fault, where
metal is contacting metal is readily visible with PeakVue long before there is
any significant increase in Overall Vibration. PeakVue is especially useful for
monitoring rolling-element bearings.
Based on years of experience with this technology, Emerson Process
Management has developed for PeakVue alarm levels, which are illustrated in
the graph below.
Figure C-3. PeakVue alarm
levels diagram.
The equations that govern this curve are: