 # Convert acceleration vibration from ADXL335 to velocity vibration

Hello,

Im currently working with my final project. The project is to monitoring motor induction with vibration sensor ADXL335, the vibration value will be compared with ISO 2372. But ADXL335 reads vibrations in units of G.
I need to convert G units to velocity since ISO 2372 is using mm/s.

I want to ask all of you is this possible to be done? Is there any suggestion to do it?

Thank you.

Acceleration is distance per second, per second. Multiply acceleration by time and the unit vull be velocity.
Rotating things usually have abnormalities like resonance frequencies and that will put a black dot over a oart of the map.
Why not use conventional technic to measure rotation?

Hi Railroader, thanks for the reply

My final project is monitoring induction motor vibration using ADXL335, not to measure the rotation.

"Multiply acceleration by time and the unit vull be velocity."

Yes you are right, but is it possible to convert acceleration to velocity without integrating?

What do You mean by the word "velocity"?
The momentary speed between the ends of the micro move?
What is the overall theory and goal?
You can use Your own standards, Your own units if You only want to compare different items.

What I mean about velocity is the velocity of the vibration.

ISO 2372 is the standardization for vibration severity in velocity units,
so that's why I need to do the conversion from acceleration (ADXL335) to velocity

Hi,
Welcome to the forum.

The vibration is an oscillating motion, back and forth, there is no constant velocity, it is changing not just magnitude but direction all through the vibration cycle.
All I can think is velocity is calculated from frequency and deflection, to give an average velocity.

Can you post a link to ISO2372?

Tom... Hi,
I found the ISO, velocity is measured in mm/sec RMS, so it looks like it uses the frequency and the DISPLACEMENT to get that figure.
@wendy248, I think you need to consult your lecturers or tutors about how this figure is attained, they would know more.

Hi,
So just possibly a 50Hz vibration of magnitude 2mm would be.

~~2mm over 1/50 = 0.02seconds ~~ Sorry only half the cycle

Velocity = 2mm/0.01Seconds = 200 mm/Second Peak.

==
200mm/Second / sqrt of 2 = 200 / 1.414 = 141mm/Second RMS

Just a top of the head dimensional analysis.
(I stand corrected, if anyone has some other input)

Tom.. :o

but is it possible to convert acceleration to velocity without integrating?

No.

Assuming a sine wave vibration in one dimension at angular frequency w, and ignoring phase

acceleration = Asin(wt)
velocity = (A/w)cos(wt) after integration.

If A is in units of g (1 g = 9.8 m/s/s) then the velocity will be (9.8/w)*A in m/s.