Converting Acceleration (g) to Sound (dB)

How :- Drop an empty metal petrol can from 3m up - it should go 'clang'. (g converted to dB)

Why - to prove that "empty cans make the biggest noise"

Thanks for your reply.But my application is different.I have one control unit to check the Noise level.If the noise level is crossing beyond the limit.My entire system will stop.

I have one more instruments(Recorder + Accelerometer) which can measure Vibration of the crank Shaft (Vibration due to misalign inside the AXLE).I can not put any sensors inside the axle but I can feel the misalign of the Tooth through Vibration.If I use Microphone for measuring noise ,I can not measure as environmental noise is very High.

My control Unit can know only the dB value.

So,What I am trying to do is : I will measure the Vibration at three points of the axle and if the Vibration level which is converted to equivalent Noise dB level which is input to Control Unit (as my Control unit can access only dB type)is crossing limit then the system will stop.

I would like to know more If we have any other solutions !!!

Seba

Have you considered using something like a guitar pickup.

Your best solution might be with MEMS technology. Google it and have a look.

guita pickup is a electromagnetic inductor. the principle is close to dynamic mic. differnt from accelerator.

#1 thread must make a kidding to you.

Im out of door to the machine porject, what I can tell is this db is fferent from that db. the distinct different among db is very remarkerable. even in sound measure, there are serveral db to read.

so you hve to use the same display unit, i,e your control unit.

there is a common way to detect your signal from noise, ie pll, or say autocorrelation function. your unit may have this function.

many machine engineer can use this way to measure vibration frequency.

This is something I've tried telling other posters.

Give a clear description of your problem so that good answer can be given. At the same time, you can avoid being ridiculed or chastised for asking a vague question.

To answer your original question...

A vibration sensor gives a signal in units of mm/sec. Simply speaking, it gives how many millimeters of movement the object is making (in this case, back-and-forth). It doesn't measure frequency although some models may have that capability.

Some vibrations are so slow that a microphone might not be able to pick it up. An inductive pickup, properly designed and installed, might do a better job but you'll need to convert the amplitude and frequency to mm/sec by experimentation.

I'm assuming you're not measuring axle vibration in a vehicle since your readings would be all over the place as the vehicle is travelling.

Vibration unit will be in m/s2.I would like to know the measure value of vibration from my Axle (Not on road .But only in Lab using test rig ).I want to check whether my assembly inside the Axle is correct or wrong.While it is testing in test rig ,If our assembly was wrong,it will give small amount of Noise which I can not measure by microphone (use for measuring noise) as the environmental noise is very noisy.I can not get the exact noise from inside the axle.But I have given the provision to measure the Vibration using accelerometers (in g unit or mm/s^2 unit) above the axle.I want to convert this value into the noise generated inside the axle so that I can control after feeding to the PLC or control unit.

My end data should be in Noise Level.

Yes you can. The accelerometer gives you after processing a signal proportional to the amplitude of the vibration. This signal can be used to amplify the signal of a white noise generator and you dB sensor will react to it.

If it is the simplest way that is an other question.