It is a procedure that differentiates
between synchronous and non-synchronous frequencies. When applied properly,
it is a powerful tool.
-
The analyzer and photoeye are set up
as outlined on the previous page.
-
The analyzer is instructed to collect
a spectrum. The specifics on how to perform this are different for each
box and exact instruction will be left to the various manufacturers.
-
The analyzer will collect a spectrum
that contains ONLY synchronous vibration. That is, only vibration
frequencies that are exact harmonics of the trigger rate (usually 1x rpm).
-
Any non-synchronous frequencies - no
matter how close they are to being synchronous - are filtered out and disappear
from the spectrum. This allows for comparison with a normally collected
spectrum and subsequent analysis of whether a particular frequency is coming
from the rotor or some other (non-synchronous) source.
For more information on this powerful
troubleshooting tool, see the 'Field Tests' manual. |
