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karl

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Reply with quote  #1 
Hello,

Regarding ISO 10816-3 vibration severity chart are the tolerance values indicated (mm/s rms), overall values or peak values?

Hope the question makes sense.

Tks Karl
OLi

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Reply with quote  #2 
RMS https://en.wikipedia.org/wiki/Root_mean_square
normally 10-1000Hz but there are exceptions to both in various ISO doc's

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karl

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Reply with quote  #3 
Thanks for the reply OLi, however what I am trying to understand is if the vibration severity chart values relate to individual peaks (the highest) in the spectrum or the overall value in the frequency range of the spectrum
OLi

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Reply with quote  #4 
It is the RMS sum of all peaks within the specified frequency range hence the RMS so neither of your suggestions I guess.


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Shurafa2

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Reply with quote  #5 
Karl,

Maybe I understood your question. You ask about the table in the standard that shows limits for different zones based on the support and power. In ISO 10816-3, this is written "r.m.s. velocity mm/s" on the table's header.

In general, the vibration limit can be overall amplitude for the entire the sample or it could be spectral amplitude at a certain frequency in the spectrum plot. And you ask about the amplitude in this particular reference. Is this your question?

If yes, then the limits provided are the overall not the spectral amplitudes. The standard calls for broad-band measurement.

What you called "peak values" can be misunderstood with the zero-peak method of calculation while you are referring to the individual components (filtered amplitudes) on the spectrum, I guess. In the spectrum, the "peaks" can be expressed in mm/sec rms or mm/sec 0-p. Neither one of these is broad-band amplitude.

But I could be totally wrong as in many cases.

Regards- Ali M. Al-Shurafa


Walt Strong

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Reply with quote  #6 
"the overall value in the frequency range of the spectrum"

Yes, for ISO Severity in RMS velocity units. Note that it is easy to convert from mm/sec to in/sec velocity, but RMS to Peak must assume a sine wave. The same sine wave assumption must be made for conversion between velocity and displacement or acceleration.

Walt
OLi

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Reply with quote  #7 
ISO 10816-3 point to another standard normally that defines the specs of the measurement (ISO 2954 or updated), it is normally not broad band like that or at least not OA, the normal spec is "broad band" but filtered 10-1000Hz and the filter spec is brand new in the latest 10 years and are now defined in a way that it is actually possible to follow the previous was the same from the 50's I think however for machines less than 600RPM lower limit should be 2Hz . Filter range is subject to change in various standards and in some other standards it is further messed (/complicated) up. Rectification are defined as RMS in most cases but not all. If you see the word "Severity" it may indicate that the number is a compound calculation of acc, vel, amp data, not a direct measurement but not always and not in 10816-3, yet.

If your instrument is digital it may store the TWF and can calculate any number in any way you like or that you can convince the software guy to produce for you........
Or it can do a hybrid semi cheat and store the signal peak rectified also. There are many ways to skin a bear, specially if it is a digital bear.

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Mniroshan

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Reply with quote  #8 
Could you please send me a link for ISO 10816-3 Vibration severity chart for Acceleration?
OLi

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Reply with quote  #9 
It is velocity and can be purchased from the ISO organization.
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MarkL

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Reply with quote  #10 
Never seen one for acceleration? Aren't they all in velocity I thought?
Danny Harvey

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Reply with quote  #11 
We can not send ISO material because it is copyrighted and ISO, as the copyright holder has exclusive rights to distribute it.
fburgos

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Reply with quote  #12 
Quote:
Originally Posted by Mniroshan
Could you please send me a link for ISO 10816-3 Vibration severity chart for Acceleration?


There is no such standar, acceleration and displacement severity are dependant of frequeny.

unlike the ISO10816 asumes a linear severity range from 10-1000HZ, every frequency between 10-1000hz has same severity on same amplitud.

there is a severity chart/graph on this subject, I remember the rathbone and IRD
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