| Deutsche Version |
| Fill the known values in the three enter boxes and press the calculate bar to calculate the air absorption. This is the "added" air damping (dissipation of air), because this value must be added to the usual distance damping after the 1/r law. |
Acoustics - Attenuation of sound during propagation outdoors - |
Calculation of distance damping: Changing of the sound level Δ L with the distance r
| This air absorption is valid for the direct field D (free field), an outside location without contributing reflections. When calculating the additional high frequency attenuation of speaker signals in a living room caused by air absorption this formula (method) cannot to be used. Due to the additive reflections in the room field R (diffuse field of a room) the law of frequency dependent air damping does not apply. |
Composition of air
| Constant configuration (Values stay equal over time and place) |
|
| nitrate (N2) | 78.08 % |
| oxygen (O2) | 20.95 % |
| argon (Ar) | 0.93 % |
| neon, helium, krypton | 0.0001 % |
| Variable configuration (Values change over time and place) |
|
| carbon dioxide (CO2) | 0.0003 % |
| water vapor (H2O) | 0 − 4 % |
| methane (CH4) | traces |
| sulfur dioxide (SO2) | traces |
| ozone (O3) | traces |
| nitrogen oxides (NO, NO2) | traces |
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