Contact US

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Kurtosis miss indication of impacting

Kurtosis miss indication of impacting

Kurtosis miss indication of impacting

Hello Guys,
i have 2 data acquisition with 2 waveform one with impulse and one without.
I made some calculation with my instruments and it is very easy to evaluate impulsiveness of the waveform.
Why, instead, Kurtosis seems have missed this impulsiveness of the waveform?

Let me know about your opinion.


RE: Kurtosis miss indication of impacting

i'm starting to use kurtosis as "new frontier to find bearing problem" as some salesman use to sell his products.
Some other speak about technique to find impacting or impulsive signal....
I wanted to try personally and i found it is not really as aspected.
Anyway i know some technician use it with good results.
Or i have misconception about how Kurtosis work and the waveform in attach it is a rare case where kurtosis doesn't works or kurtosis is useful for other type of investigation.

I'm not really familiar with statistics and i didn't find yet a simple explanation about how Kurtosis work.

I used crest factor several time but also in this case the crest factor value is not really big. In this case is simple to say crest factor is better indication because you have a comparison signal. In any case i could not to assert impulsiveness only from crest factor because it is very low value.

RE: Kurtosis miss indication of impacting

Given that your "signal" rides on another signal of the exact same frequency, it seems dubious to extract the difference in any unfiltered means, unless you compare measurements wit, and without, the spikes. It just seems to me that something like an unsharp mask approach to extract only the high frequency spikes would be required.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers Entire Forum list http://www.eng-tips.com/forumlist.cfm

RE: Kurtosis miss indication of impacting

Fundamentally the issue is that the there is relatively little energy in the spike compared with the base sinusoid. One approach I've seen for a signal like this is to gate it, that is, average the time history for each cycle starting from the same shaft position. On the other hand, as IRStuff implies, a high pass filter may be all that is needed.


Greg Locock

New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login


Low-Volume Rapid Injection Molding With 3D Printed Molds
Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Download Now
Design for Additive Manufacturing (DfAM)
Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a part’s function at the center of their design considerations. Download Now
Taking Control of Engineering Documents
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close