Condition Monitoring

[rabbit]

What is the correct Collection Specification setup for a 5kHz gSE filter measuerment point?

[pc]

I assume this is about using an Enpac. Correct? If not, what?

[rabbit]

I have emonitor factory and would like to verify the measurement parameter setup for data collection.

COLLECTION

transducer: Acclerometer  signal detection: P-P 

window: hanning  max freq: 60000 CPM Number lines:800  Number of averages: 4

Type: linear percent overlap: 50

FILTER

5KhZ Gse

Is this the correct collection specification for this filter?

Yes I am using an EnPac for data collection.

[Ozzy]

1.) Unit's should be g's

2.) 5kHz gSE filter is usually what you use, although there are others for specific purposes.

3.) The sensor is probably fine, that selection is simply choosing one out of the calibration list, this selection is choosing the right type atleast.  The default for this one is setup for 100mv/g so if you are using a different sensor or the calibration is different you may want to adjust this or use a custom made sensor your choice.

4.) Stuff like the window, the averages, the percent overlay, and your maximum frequency depend more on what you are taking a measurement of.

Also,

Remember when you are doing percent overlay and averages you are filtering out 'random' like events; however, many events like a bearing going bad is a jumble of nearly random impacts, you may very well be filtering out what you are looking for.

So let me ask some questions of you.

What type of machine is it? Fan? turbine? pump? conveyer belt?, etc.. 

What are it's components, bearings, gears, giant swinging blades?, etc..

What is it's running speed, and other identifiable frequencies such as gear mesh, blade pass, etc. 

What is the environment?  Outside, Inside, is it next to a lot of just, perhaps a giant injection molding machine?, etc...

Just like a standard spectrum measurement we have to take these things into account when setting up a collection specification.  The more accurate this is to your needs, the more useful information you can gain.

[rabbit]

We monitor fans, chiller motors and pumps.

In the future I amy monitor rotary screw compressors, I need more information on the components and their frequencies.

we use gSE to  look for bearing problems.

speed ranges form 900 to 3600 rpm.

almost everything is indoors.

[Greg Hood · Accepted solution]

Hey rabbit! -

You have already received some good advice.

Here is a good paper that may help you answer all your questions regarding gSe.  This paper references the DPAC 1500.  But if you have your impact set to emulate the datapac all settings should be the same.  Thanks and let me know if you have further questions.