Dear All,

what is the formula or how to convert vibration reading from micron to mm/s?

thanks in advance

 

Anonymous... the conversion from microns/sec to mm/sec is:

mm/sec = 0.001 x microns/sec or mm/s = 0.001 x um,

where in SI units, mm = millimeter and um = microns or micrometers.

Regards, Phil Corso

 

I don't believe the originator asked about converting from microns/sec, rather from microns.

In vibration monitoring, displacement systems, like the Bently-Nevada system, usually express vibration in very simple "distance" measurements.

It seem the originator is trying to convert from displacement to velocity, another, different, but very common, vibration measurement.

I believe this conversion requires the RPM (or radians/sec, or some rotational unit of measure) to make the conversion. I would suggest to use an Internet search engine, like Google or Bing and type the desired conversion or look for results related to 'conversion from displacement to velocity'. One might also look at some various vibration manufacturer's websites to see if they have some conversion information. (I'd recommend Bently-Nevada's, but I find it difficult to find information on their site, as with other GE sites. Whether that's by design or not, ....)

 

CSA, thanks for the clarification, you are right I need to convert from displacement micron to velocity mm/s

regards

 

By typing:

convert displacement to velocity

into a Google search field, this .pdf was the second search result:

http://www.vibrametrics.com/downloa...ERATION MEASUREMENTS SESSION 4-19-05_comp.pdf

(remove any spaces inserted in the link by the software)

On slide 12 of the presentation I found the formula:

Velocity = Pi * (frequency / 60) * displacement

or

Velocity = 3.14159 * (frequency / 60) * displacement

or

Velocity = 0.5236 * RPM * displacement

[Frequency = RPM / 60]

Just make sure your "microns" are metric since you want your velocity in metric units.

It seems most of the major search engines will accommodate questions, or some form of them. Be creative with terms in search engines; don't be afraid to "fail", and even if you find something, if you can think of other possible terms or ways to express the same thing, try them, too. You may be pleasantly surprised!

 

<b>CORRECTIONS</b>

Every formula in the previous post was incorrect! (I should have just listed the reference and been done with it....)

The correct formula are:

Velocity = <b>0.05236</b> * RPM * displacement

The first formula should have read:

Velocity = Pi * frequency * displacement

And the second formula should have read:

Velocity = 3.14159 * frequency * displacement

where frequency = (RPM / 60)

<b>SINCERE</b> apologies for any confusion!

In the event there are any other transcription errors, the formulae in the listed URL win!

 

CSA, thanks for the clarification, you are right I need to convert from displacement micron to velocity mm/s

 

Dear CSA,

the frequency you are talking abt is frequency of vibration or is it the frequency of shaft rotation eg in case of a gas turbine?
If it is frequency of vibration then how to get this value for making conversion from mm/sec to microns?

thanks n regards;
ashish

> <b> CORRECTIONS</b>

> Every formula in the previous post was incorrect! (I should have just listed the reference and been done with it....)

> The correct formula are:

> Velocity = <b> 0.05236</b> * RPM * displacement

> The first formula should have read:

> Velocity = Pi * frequency * displacement

> And the second formula should have read:

> Velocity = 3.14159 * frequency * displacement

> where frequency = (RPM / 60)

> <b> SINCERE</b> apologies for any confusion!

> In the event there are any other transcription errors, the formulae in the listed URL win!

 

> Velocity = 3.14159 * frequency * displacement
>
> where frequency = (RPM / 60)

Unfortunately, the link above is "missing" since the referenced site has been "replaced." But, the answer to your question is still in the reply, as above.

 

in my plant turbine rpm is 7500, front shaft vibration is 25 micron. putting values on your formula, i got 9812 m/s which is not acceptable. boss clear my question if u have any idea.

 

Dear sir,

Rotating Equipment like pump & compressors vibration reading in terms of velocity measure, ie mm/sec.

sometimes we using the terms microns um.

Can you clear me 1 mm/sec = how many microns?

Formula result not really matching the expected microns which is around 10 microns .

i don't know the formula ... could please any one clarify?

<b>CORRECTIONS</b>
>
>Every formula in the previous post was incorrect! (I should
>have just listed the reference and been done with it....)
>
>The correct formula are:
>
>Velocity = <b>0.05236</b> * RPM * displacement
>
>The first formula should have read:
>
>Velocity = Pi * frequency * displacement
>
>And the second formula should have read:
>
>Velocity = 3.14159 * frequency * displacement
>
>where frequency = (RPM / 60)
>
><b>SINCERE</b> apologies for any confusion!
>
>In the event there are any other transcription errors, the
>formulae in the listed URL win!