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Strutt|Environmental Noise|Atmospheric Attenuation inserts attenuation (dB), due to atmospheric conditions, into the active row of the worksheet.

The input required is selction of the method to use (CONCAWE or ISO 9613.2), temperature, humidty and propafation distance.

CONCAWE references Tables 1 - 7 (CONCAWE), which give atmospheric absorption Values, dB km^-1, from 0ºC to 30ºC for 55 - 100% relative humidity. This value is then multiplied by the propagation distance (converted to km) to calculate overall atmospheric attenuation.

ISO 9613.2 references Table 2 (ISO 9613.2), which gives atmospheric attenuation coefficients, dB km^-1, for various temperatures and % relative humidity. This coefficent is the multiplied by the propagation distance (converted to km) to calcluate overall atmospheric attenuation.

References:

• Manning, C.J., The propagation of noise from petroleum and petrochemcial complexes to neighbouring communities (CONCAWE), p26, Tables 1 - 7
• ISO 9613-2, Acoustics - Attenuation of sound during propagation outdoors - Part 2: General method of calculation p5