Datasheet

2 Fluke Corporation Fluke 805 Vibration Meter
What is Crest Factor +?
Fluke 805 with Crest Factor + takes the
confusion out of bearing assessment
The original Crest Factor is used by vibration analysts
to identify bearing faults. It is defined as the ratio of
the peak value/RMS value of a time domain vibration
signal.
A key limitation of using Crest Factor to iden-
tify bearing faults is that the Crest Factor does not
increase linearly as the bearing degrades. In fact, the
Crest Factor can actually decrease as a bearing nears
catastrophic failure due to large RMS values.
In order to overcome this limitation, Fluke uses
a proprietary algorithm known as Crest Factor +
(CF+). CF+ values range from 1 to 16. As the bearing
condition worsens, the CF+ value increases. To keep
things simple, Fluke has also included a four-level
severity scale that identifies the bearing health as
Good, Satisfactory, Unsatisfactory or Unacceptable.
What is Crest Factor +?
Exporting and Trending
with the 805
Export and Trend in Excel
Trending, or repeated vibration measurements kept in
a spreadsheet over time, is the best method to track
machine health. With 805 you can easily:
• Export your result to Excel through USB connection
• Trend the readings with the pre-built Excel
templates and plot graphs
• Compare the overall vibration readings to ISO
Standards (10816-1, 10816-3, 10816-7)
Import measurements from the 805 Vibration Meter
to an Excel template on your PC in order to trend
the bearing parameters: overall vibration, CF+, and
temperature. Looking at just the number alone for the
overall vibration or temperature might not be of much
benefit to the operator or technician if they don’t
know what the number means. The user may not
know what is normal or what indicates a problem.
If measurements taken on the operator rounds are
easily loaded into Excel, then the trend will show
patterns of something that is becoming abnormal.
The user can now see a clear picture of the changing
bearing condition and deteriorating health of the
machine.
Bearing Vibration
(CF+)
Overall Vibration
IR Temperature
High Frequency
4,000 Hz to 20,000 Hz
Overall Vibration
Frequency Range
10 Hz to 1,000 Hz
Temperature
-20 °C to 200 °C
Sample trend plot using the Fluke 805 trending template.