Sound Power Level definition

[Cewek ITS]

Dear All,

I get question from my colleague, but I am confused how to define it clear and understandable. What does Noise power level in fan exactly mean ?

BR

[nike123]

Google is your friend, my friend!
http://en.wikipedia.org/wiki/Sound_power_level
http://en.wikipedia.org/wiki/Noise_level

[nh3simman]

Sound power is a function of the machine. It doesn't matter where you stand, it is a fixed value.

Sound pressure is what you hear. This value is affected by attenuation in the ducting, the room absorptance and the distance from the listener.

A small confusion is that both have the same units (decibels).

[mkardehi]

Hi;
measuring sound pressure has different standards and classes which differents are on weighting diffferent frequencies .... for example class A is weighted frequencies which human can hear . you can find more on google .
good luck