Repeatable Reading variation in Noise & Vibration Analysies

We are testing the Quality of the gears based on the noise and vibration produced when the bevel and the pinion gears mesh each other. We Using SV DAQ NI PCI-447 and connected accelerometer and microphone for 1st and 4th channel respectively. We are following signal harmonics method for the testing purpose. First, we acquire the data signals of both noise and vibration and process them by the same above method and judge wheatear the gear has some defects or not. (Based on the threshold values) The problem is, each time when we run the machine, the noise and vibration signals which we acquire will be different due to this final results (Harmonic values) are also changing. We need some filters or any other solution so that we acquire noise and vibration only for gear mesh. I uploaded a picture showing how we doing the test process for sound.
Attachments:
harmonic.png ‏35 KB

If you are only concerned about peaks within a certain frequency range, you should adjust the Search Range in the settings of the Peak Search Express VI (on the Configuration tab). That will tell the express VI to only return the peaks in the frequency range that you choose.
To clean up your results, you may want to try some FFT averaging. This might help if your peaks are jumping around a little bit due to a low peak threshold that might be picking up some noise.
If you really would like to do some filtering, you could use a highpass filter to get rid of any low order (1x/2x/3x, etc) vibration that you might not care about. From your picture, it looks like you have the Sound & Vibration Measurment Suite and you are comfortable using express VIs. So, you could use the filter express VI from the palette here: Sound and Vibration>>S&V Express Measurements>>Processing>>Filter.

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Sound & Noise Vibration Analysis

Hi
We are testing a machine " Hypoid Gear Tester" basically for Acceptance or Rejection of Gear Production. We are testing PC base Labview software for this. We are using Microphone & Accelerometer for Analysis. The Enviroment is noisy 1) How to determine and elliminate this external noise 2) We need to generate a Graph or report as the attached file. I appreciate your help Thanks
Attachments:
Picture 022.jpg ‏595 KB

The order analysis tools and the sound and vibration tools provide the fundamental signal analysis for most all machinery vibration functions. However, the application level such as hammer blow test (modal), balancing, and so forth are not complete solutions.
I recommend looking at the following solution, which is based on these tools and comes with a turn-key application solution....
www.vibdaq.com
Let us know what further questions you have.
Preston Johnson
Principal Sales Engineer
Condition Monitoring Systems
Vibration Analyst III - www.vibinst.org, www.mobiusinstitute.com
National Instruments
[email protected]
www.ni.com/mcm
www.ni.com/soundandvibration
www.ni.com/biganalogdata
512-683-5444

Noise, Vibration & Order Analysis

Dear all,
I am currently looking for a program that can perform a noise, vibration and order analysis. I was just made aware that LabVIEW (Developer Suite, if I'm not mistaken) comes with Noise and Vibration and Order toolkits. I've read through the data sheets for both toolkits. Now, I'm wondering whether the two mentioned toolkits can perform the analysis below:
1. Vold-Kalman Order Tracking Filter
2. Modal and Structural Analysis
3. Noise Source Identification
4. Modal Test Consultant
5. Acoustic Test Consultant
6. Real time CPB Analysis
7. Rigid Balancing and Two-Plane Balancing Consultant
8. Baseband FFT Analysis
9. Signal Enhancement
10. Auxiliary Parameter Logging
11. Cepstrum Analysis, and
12. Envelope Analysis
These analysis modules can be performed by Bruel & Kjaer product. I'm trying to influence my superior that National Instrument can also achieve the same objectives. So, maybe the users out there, or NI technical experts can help me with this. If the two toolkits are insufficient to perform such tasks, but NI has other toolkits that can supplement, can you guys please mention it in your reply.
Many thanks!
Shazlan

The order analysis tools and the sound and vibration tools provide the fundamental signal analysis for most all machinery vibration functions. However, the application level such as hammer blow test (modal), balancing, and so forth are not complete solutions.
I recommend looking at the following solution, which is based on these tools and comes with a turn-key application solution....
www.vibdaq.com
Let us know what further questions you have.
Preston Johnson
Principal Sales Engineer
Condition Monitoring Systems
Vibration Analyst III - www.vibinst.org, www.mobiusinstitute.com
National Instruments
[email protected]
www.ni.com/mcm
www.ni.com/soundandvibration
www.ni.com/biganalogdata
512-683-5444

Rule of thumb for the number of averages in an FFT for vibration analysis?

I'm doing vibration analysis on rotating machinery and would like to average the FFT to minimize variations of the data (rms averaging). How does one choose the optimum number of averages?
Also, why is it necessary to specify the number of averages (for example, in the Spectral Measurements express VI) as well as telling the VI to restart averaging. Would not the latter would be sufficient when the Spectral Measurements VI is enclosed in a loop? Thanks.

Thanks for your post.
In my experience 20 is a good number. It really depends however on a number of factors.
1) does the frequency of the rotation of the machine (speed) change? If so, averaging from an FFT would not work well. I would use the Order Spectrum in the Sound and Vibration Measurement Suite if speed changes.
2) are loads changing (and speed is constant or you are using order spectrum)? If so you will want a smaller number of averages so you do not average out the effect of fast load changes.
3) try a few numbers and note when the noise floor appears stable. This may be the best method to choose the number.
4) how often do you want a result? A smaller number of averages will produce an "averae complete" result more often.
Use the averages complete boolean to gate passing on the results (to the user interface, file, further analysis, etc.). With restart averaging on, it will restart another averaging process and toggle the boolean (gate).
Hope this helps.
Preston Johnson
Principal Sales Engineer
Condition Monitoring Systems
Vibration Analyst III - www.vibinst.org, www.mobiusinstitute.com
National Instruments
[email protected]
www.ni.com/mcm
www.ni.com/soundandvibration
www.ni.com/biganalogdata
512-683-5444

About Vibration analysis of machine using wavelet analysis and extraction techniques

I want to perform vibration analysis using accelerometer and NI DAQ please help me in VI development and how and which parameters should i extract from the raw signal. About Vibration analysis of machine using wavelet analysis and extraction techniques.
Nitesh Parmar
+91-9780900184
[email protected]

Lynn,
Thanks for the reply.
I'm attaching some pictures of the test rig. As you can see, we have a small servo motor sitting on top of the bearing, which is a small needle/thrust bearing, used in the planetary gears of automatic transmissions. The readings are being taken by a general purpose 100mV/g accelerometer, which you can see is mounted on the bottom of a fairly thick steel plate. I understand there can be some transmissibility problems when going through too much material? We seem to be getting a reading though. The only weight on the bearing is the motor and mounting plate, 5-10lbs. I considered adding weight, and that will probably be my next move.
I'm also attaching some runs I've made. One set is of a brand new bearing, the other set is of one I stuck in a sandblaster. It is now very obviously damaged, rough and noisy when you turn it. You should be able to open these files with the .vi attached to my previous post. The first tab will be the waveform, raw data. It is not accurately calibrated to g's, but I think it should be in the ballpark. The runs are comparable to each other anyway.
I'm not currently alligning the readings with the motor revolution. Maybe this is something I should look into? I have a very capable motor/drive setup for this...
I was previously using a legacy daq device, with which I couldn't wire the error lines into the digital line write tool. You are correct that I can now remove the while loops.
Whatever else I can provide to help you assist me here, let me know.
Thanks for the feedback.
Jeremy Backer
CLAD
Attachments:
Bearing Pics.zip ‏898 KB
Brand New.zip ‏3429 KB
Sand Blasted.zip ‏3426 KB

Isolation level: repeatable read vs read stability.

I was going through the following link [http://www.developer.com/print.php/3706251] about database isolation levels. There was a statement:
In Read Stability, only rows that are retrieved or modified are locked, whereas in Repeatable Read, all rows that are being referenced are locked.
What is meant by "all rows that are being referenced".
According to my understanding in case of repeatable read, the table is locked. Is this understanding correct?
Edited by: user476453 on Oct 29, 2010 2:03 AM

This article is referencing DB2 isolation levels and not Oracle ones: isolation levels are standardized in SQL but practically they can be very different from one database to another. For Oracle please refer to http://download.oracle.com/docs/cd/E11882_01/server.112/e16508/consist.htm#CNCPT621.
Your DB2 question should be posted on DB2 forum and not on an Oracle forum.

SP2013 Bug Report: Health Reports - You can only specify the READPAST lock in the READ COMMITTED or REPEATABLE READ isolation levels.

There appears to be an error when trying to view Health Reports from Central Administration. A simple fix within a SharePoint Stored Procedure fixes the problem. I get the error message "You can only specify the READPAST lock in the READ COMMITTED or
REPEATABLE READ isolation levels." when just trying to click "View Health Reports" --> Go in CA.
I have found the same problem in some blog posts which leads me to believe this is a bug:
Problems Viewing Health Reports in SharePoint 2013
From the blog post "I managed to work around it by altering the
proc_GetSlowestPages stored procedure and commenting out the
WITH (READPAST) line. "
This also worked for me. It would be great if a fix could be released for this problem as it seems to cause other problems as well (site analytics freezes).

Hi Dennis
Hope you had found the hotfix and installed it.
For the benefit of others who visit this thread SharePoint Server 2013 Client Components SDK hotfix package addresses this issue.http://support.microsoft.com/kb/2849962
Regards
Sriram.V

Serializable Vs Repeatable read

Hi All
What is the difference and exact usuage of the parameters Serializable Vs Repeatable read in Sender JDBC Adapter?
Thanks
Sai

Hi Sai,
What is the difference and exact usuage of the parameters Serializable Vs Repeatable read in Sender JDBC Adapter?
Go through this links,
http://help.sap.com/saphelp_srm40/helpdata/pt/7e/5df96381ec72468a00815dd80f8b63/content.htm
https://www.sdn.sap.com/irj/sdn/go/portal/prtroot/docs/library/uuid/6a90d6aa-0b01-0010-8a83-cf0e6c70dcce
Sender JDBC Adapter
/people/yining.mao/blog/2006/09/13/tips-and-tutorial-for-sender-jdbc-adapter
http://help.sap.com/saphelp_nw04s/helpdata/en/22/b4d13b633f7748b4d34f3191529946/frameset.htm
http://help.sap.com/saphelp_nw2004s/helpdata/en/22/b4d13b633f7748b4d34f3191529946/content.htm
https://www.sdn.sap.com/irj/servlet/prt/portal/prtroot/docs/library/uuid/3867a582-0401-0010-6cbf-9644e49f1a10
/people/sap.user72/blog/2005/06/01/file-to-jdbc-adapter-using-sap-xi-30
/people/yining.mao/blog/2006/09/13/tips-and-tutorial-for-sender-jdbc-adapter
/people/sameer.shadab/blog/2005/10/24/connecting-to-ms-access-using-receiver-jdbc-adapter-without-dsn
/people/saravanakumar.kuppusamy2/blog/2005/01/19/rdbms-system-integration-using-xi-30-jdbc-senderreceiver-adapter
Thanks,
Satya
Edited by: SATYA KUMAR AKKARABOYANA on May 8, 2008 4:52 PM

Portable vibration analysis cRIO technology???

How can I do a portable vibration analysis with cRIO technology and LabVIEW software?. Is it possible a FFT analysis in situ with
a PDA?. I relly apreciated your help. Thanks.

Jorge,
With this setup you would have several options. The cRIO actually has a processor on it that will allow you to run LabVIEW Real-Time programs for acquisiton, process and logging. The cRIO controller also has a network link on it allowing for transfer of data over a wireless network if desired. Though a PDA could perform the FFT, the processing power required may be a little taxing on the weaker performing processors found in most PDAs.
Let me know if you need any more information.
cheers,
Brett

You can only specify the READPAST lock in the READ COMMITTED or REPEATABLE READ isolation levels

Hi, I have a piece of code that works fine in SSMS as T-SQL. When I put the T-Sql inside a SP, I get the error :
You can only specify the READPAST lock in the READ COMMITTED or REPEATABLE READ isolation levels
The script starts is as follows (only select)
SET NOCOUNT ON
Set Transaction Isolation Level Read Committed
Set Deadlock_Priority Low
Select......
From MyTable WITH (NOLOCK)
GROUP BY .....
Order BY ....
works fine as I said in SSMS as T-SQL but the SP generates the following
Msg 650, Level 16, State 1, Procedure usp_TotalMessages, Line 15
You can only specify the READPAST lock in the READ COMMITTED or REPEATABLE READ isolation levels.
By the way, when it says line 15, from where we should start counting, is it from The USE DB statement which includes comments as well as Set ANSI....or should we start counting from the Alter PRocedure statement
Thanks in advance

Set Transaction Isolation Level Read Committed
Set Deadlock_Priority Low
Select......
From MyTable WITH (NOLOCK)
GROUP BY .....
Order BY ....
First you define transactionlevel = "Read Committed", then you use a query hint "NOLOCK" which is equivalent to "Read Uncommitted"; so what do you want now, committed or uncommitted, you have to decide.
Olaf Helper
[ Blog] [ Xing] [ MVP]

Noise & vibration

Hi
We are collecting the data of a machine which produces noise & vibration. During each trial run we are getting different values can any one help to solve this problem.
Thanks

We are testing the Quality of the gears based on the noise and vibration
produced when the bevel and the pinion gears mesh each other.
We Using SV DAQ NI PCI-447 and connected accelerometer and microphone
for 1st and 4th channel respectively.
We are following signal harmonics method for the testing purpose. First, we
acquire the data signals of both noise and vibration and process them by the
same above method and judge wheatear the gear has some defects or not. (Based
on the threshold values)
The problem is, each time when we run the machine, the noise and vibration
signals which we acquire will be different due to this final results (Harmonic
values) are also changing. We need some filters or any other solution so that we
acquire noise and vibration only for gear mesh.
I uploaded a picture showing how we doing the test process for sound.
Attachments:
harmonic.PNG ‏35 KB

Sound and Vibration toolkit for vibration analysis

Hi guys! I am new to Labview. I am trying to use Sound and Vibration toolkit to analyse the accelerometer signal mounted on a motor through myRio. The analysis are spectral map, order tracking, power spectrum, order spectrum etc. But nothing can be seen from the output graph. The only result I get is from vibration level.
Attached is a screen shot of my vi and actual vi file. Am I doing it correctly? I really need your help guys....
Thanks.
Attachments:
Vib.vi ‏384 KB

SK,
You have serious problems in your File.VI. Why are your writing to your file and then reading it right back? Worse, there is no guarantee that the File write will actually occur before the File Read. You have a race condition set up there between those two Spreadsheet File VI's.
If you want to maintain a history of whatever has already been written to the file, you should be building it into an array and storing in a shift register. Even if your File.vi would by chance work the way you want it to, storing data in the file system is much slower than maintaining your data in memory.
As for your while loop, it is going to run as fast as it can with respect to all the functions occurring inside of it. Is it possible you are getting 14 iterations of that while loop for each frequency step that is occurring?
Message Edited by Ravens Fan on 07-25-2009 01:35 AM

Weird noises, vibration and battery?

Okay, so I've just recently noticed that when I tilt my Macbook Air OS X, version 10.9.4, (schoolcomputer) doesn't quite work as usually.
First off, my usbports doesn't work - none of them. This happened like a week ago, and i've never used all of them, just one.
And then tonight when I tilted my mac to the sides there was weird noises sounding, like when you shake your keys.
After that my whole mac started vibrating, and it still hasn't stopped.
And my battery was at 4%, but then suddenly changed to 8%
oh yeah and also, it gave me an electric shock earlier yesterday, but it was only one and nothing happened afterwards, so I just shook it off.
Is it broken or what's happening?

You should make an appointment with an Apple Genius, bringing both the computer and power adapter with you, and discuss your options.

Read Only Access while assigning Analysis Types and Reports in User/Group

Hi Team,
While Assigning Analysis Type,Reports and Workbooks to User "Read" option is not enabled. It is not working and as soon as we select analysis type ,Only one option is editable "Create/Update/Delete". The other two Option is always there as display "Read" and "Execute" . Execute might work with "Scripts template" but "READ" should work for analysis types and Reports.
We are already struggling with "Read Only" Access in security filter as its not working now.
Thanks
Edited by: user7918731 on Mar 2, 2011 11:22 AM

The behavior for Analysis type, workbook and script as follow:-
The Analysis type create/update/delete option will be enabled, read and execute option will be disabled by default.
The report workbook read option will be enabled, and other two options will be disabled.
The script execute option will be enabled, and other two option’s will be disabled.
For providing “Read Only” access in security filter, Switch to the administration tab, Click on Security Filters, Click on Add button, Open Create Security Filter window, Select the access level to Read Only and select user in assigned user , Click on ok.
It should work.

Having difficulty reading data file and doing analysis, maybe DIAdem can help

Hello,
I am new to DIAdem but I think it may be helpful to my application.
I used Write Labview Measurement File VI with n-signals input to generate a data file containing 2*n columns(time column and data column iteratively). Now I need to do data analysis from the file. I'd tried to use Read Labview Measurement File VI to load the data but didn't work. I found that it can only read file with one signal as input and without file header. But why?
What I want to do is to extract specific columns from the file. Some column has special flag values which divide the column into sections. I also need to extract these sections from the column and plot each of them. I know this can be easily done on other data analysis software but is there any way I can do it on Labview? Can DIAdem help with this?
Thank you

Hello,
To answer your last question first, DIAdem can certainly help. You can open the TDM file you created with the Write LabVIEW Measurement File VI with DIAdem. If you navigate to the TDM file in the External Data window of DIAdem NAVIGATOR, you can drag and drop the file into the Data Portal and use the channels of data at will.
You can also right-click on the file in the External Data window and choose Selective Opening…. There is a Help button in the Selective Opening window which will tell you more about using this feature.
Either way, once your data is in the Data Portal, you can use the DIAdem ANALYSIS to perform a wide range of analysis on your data. For more on the capabilities of DIAdem, I recommend starting at NI DIAdem.
Now, in regards to using the LabVIEW to access the data in your TDM file, this is also possible. If you are using LabVIEW 7.1, you will want to look at the Read Channel Groups example. This example uses a sequence of VIs from the Functions>>All Functions>>FileI/O>>Storage palette. The example demonstrates reading multiple channels from a TDM file.
Regards,
Eric M

Repeatable Reading variation in Noise & Vibration Analysies

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