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bsr201283

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Reply with quote  #1 
Dear sir/ madam,

We are in process of choosing right accelerometer for motor vibration analysis.

What is the maximum bandwidth requirement for motor vibration analysis ?

Shurafa2

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Reply with quote  #2 
To help, I'm afraid you need to give more details about the case.

Some of the forum members are/were in the user side and many members are/were in the vendor side. Users can give you part of the specifications and vendors can specify models.

But everyone  needs to know the type and speed of the equipment before giving a guess. 

Regards- Ali M. Al-Shurafa 


Vibe-Rater

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Reply with quote  #3 
There is a bit of a story to that in my opinion. So for motors they will be 2 pole, 4 pole, 6 pole and slower. So you will be looking for 3.08 x. and yesy I am thinking in orders.  It is always the same regarles of speed. Whether you are in USA or Eorope / Australia. So a good quality 100 mv/g will do you. I stilll have Wilcoxons that have incredibly low setttling times. I tried IMI and CTC all no good with the speed I collect a walk around vibration program.  Not sure if Wilcoxons ar estill avalable. rgds

Vibe-Rater

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Reply with quote  #4 
Not to say that afrorementiond are no good, they are very good. Only critisism is the settling time.

bsr201283

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Reply with quote  #5 
We have some accerometers , part numbers are adxl345 , lis3dh and isn330dls.

Adxl345 have 1600 Hz bandwidth 1.6 samples/1ms
Lis3dh have 2500 Hz bandwidth 2.5 samples /1ms
Ism330dls have 3300 Hz bandwidth 3.3 samples / 1ms

We want to use in all types of motors. For proper analysis what is the maximum bandwidth we can select..

I mean no of samples we need per 1 msec time.
fburgos

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Reply with quote  #6 
Ohhh you're talking about bandwidth as in sending signal.... You mean a vibration transmitter to be honest depending on your application any will work or none
fburgos

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Reply with quote  #7 
Forget about my last post, a quick search on Google they are accelerometer for Arduino, can't say they are not suitable for what we do since I couldn't find any frequency response specification or sensitivity, or frequency range (how many frequencies are included) it's different as your bandwidth (frequency of sampling)

 
Attached Files
pdf ADXL345.pdf (855.21 KB, 7 views)

OLi

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Reply with quote  #8 

Be seriously aware and verify ADXL stuff antialiasing function. I lost 2 man year developer time messing with such ending up that Analog Devices suck and have no clue on what they are doing[mad]
and they don't care to fix it. Diagram on filtering in the datasheet is just what they wanted to do, not what they ended up getting and it was not, it alaised like hell.

You need minimum 1500Hz for a motor you need 12kHz for the bearing condition, believe me I am producing and developing these things since 1992.....
No MEMS solution are cost effective yet and the raw sensors are noisy as hell.


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Good Vibrations since early 1950's, first patented vibrometer 1956 in the US.
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MarkL

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Reply with quote  #9 
I agree with Oli, I had a guy from that company try to get my business with a new system they have last year, was laughable the inadequacies of the system, and he arrogantly tried to tell me, 'well analog are market leader in sensing and have done a lot of work on this' I said, bull, they are trying to make a quick buck on the latest flavour of the month. I didnt do anything with them. 

I think your looking at a whole lot of pain or disappointment in the longterm, sounds like a school project to me, rather than a serious effort to do condition monitoring.
Just my two cents.
OLi

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Reply with quote  #10 
Hear, hear, look at the other thread where I hid the next gen view ( my sons are hard core open source fighters) that this technology should be open source to be "improved" by the community to the level of our at least minimum denominator, what about that? It would maybe marginally stir the nest a couple of inches? 
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Good Vibrations since early 1950's, first patented vibrometer 1956 in the US.
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