## How to convert acceleration value to decibel dB?

## How to convert acceleration value to decibel dB?

(OP)

Dear all,

I measure the acceleration of the collision of the inner parts as an outcome of the noise vibration, with the sensitive acceleration sensors.

How can I convert the acceleration value of 90 m/s^2 to decibel value?

Thanks in advance.

I measure the acceleration of the collision of the inner parts as an outcome of the noise vibration, with the sensitive acceleration sensors.

How can I convert the acceleration value of 90 m/s^2 to decibel value?

Thanks in advance.

## RE: How to convert acceleration value to decibel dB?

## RE: How to convert acceleration value to decibel dB?

I am not certain if frequency information is required, or not.

## RE: How to convert acceleration value to decibel dB?

dB (La) = 20 lg (a/ao) dB re 1 µm/s2.

Acceleration Reference Level (ao) = 1 μm/s2 ≡ 0 dB (also defined in ISO 1683) *

An increase or decrease in acceleration of 20 dB = a factor of 10

An increase or decrease in acceleration of 40 dB = a factor of 100

An increase or decrease in acceleration of 60 dB = a factor of 1000 etc.

(Vibratory) Acceleration Level Definition.

IEC 801-22-09, logarithm of the ratio of a given (vibratory) acceleration to the reference acceleration. Acceleration level in decibels is 20 times the logarithm to the base ten of the ratio.

● Note 1 unless otherwise specified, the reference acceleration is 1 μm/s2 *

● Note 2 unless otherwise specified, the accelerations are understood to be expressed in RMS values.

* ISO 1683 also states 'in connection with structure-borne sound, a vibratory acceleration reference value of 10 μm/s2 is also in use'

From <http://www.acoustic-glossary.co.uk/definitions-a.h...;

Walt

## RE: How to convert acceleration value to decibel dB?

But it is kind of complex equation to interpret.

dB (La) = 20 lg (a/ao) dB re 1 µm/s2.

For example what is "re" in the equation above?

I get the decibel values at the LHS of equation when I plug the values for a 6 m/s^2 and a0 = 10µm/s2, as 115 dB?

## RE: How to convert acceleration value to decibel dB?

## RE: How to convert acceleration value to decibel dB?

a0 = 10µm/s2 is ref. value, than 0dB -> 10µm/s2.

In this case, how you calculate the dB ?

## RE: How to convert acceleration value to decibel dB?

For example, if the reference acceleration, ao, is 10 um/s2 and the measured acceleration, a, is 15 um/s2, then the measured acceleration, expressed in decibels, is 20*log(15/10) = 3.52 dB.

As an aside, in my work, I rarely find that it makes sense to use dB. For typical accelerations and velocities, it just causes confusion. Aside from people not indicating the reference, 10*log(a/ao) is sometimes used, so you need to say which equation you're using.

## RE: How to convert acceleration value to decibel dB?

My old HP 20S calculator gives 115.56 dB Referenced to 10.0 µm/s2, and 135.56 dB Referenced to 1.0 µm/s2 for an acceleration value of 6.0 m/s^2. As you can see the dB value depends on your choice of Reference Value (Re). A factor of 10x is equal to 20-dB.

Walt