What is the difference between the filtered orbit and unfiltered orbit. To my understanding, the filtered orbit takes measurement at 1 X , 2X ....Then what is the meaning of unfiltered orbit and application.Do not understand and hope to get explantion in this forum.Thanks.

A filtered orbit is constructed with only one frequency component (typically 1x). It will always look like a circle, an oval, a tilted oval, or a line.

An unfiltered orbit has all available measured frequencies present. If there are multiple frequencies present, then it will not be a simple shape like the filtered orbit..

Maybe others can add more explanation...

I believe it has been also implied in the original question the issue of information carried by filtered and unfiltered orbits.

Gevenag
The unfiltred orbit show the real moviment of shaft in the support.
it mean transitory events as rubbbing, impact etc. Some this event no have stable spectra.

Unfiltred orbit have function of the time wave form.

Ricardo Góz from Brazil

Precisely, the unfiltered orbit is the same as looking at a time waveform in an XY presentation, which depicts the actual shaft motion, but also depicts the effect of shaft runout, glitch, etc. The key is that there are a number of malfuctions that are at frequencies other than 1X, and looking at an unfiltered orbit allows one to diagnose these malfunctions.

A picture might be worth a thousand words...

The attached shows some representative direct and filtered orbits with the time waveforms that Steve mentions.

John

orbits.pdf (39 Kb, 40 downloads)

Thanks for the replies. The picture gives good understanding on this subject.