BS EN ISO 2922:2020 pdf free.Acoustics – Measurement of airborne sound emitted by vessels on inland waterways and harbours.
BS EN ISO 2922 This document specifies the conditions for obtaining reproducible and comparable measurement results of the airborne sound emitted by vessels of all kinds, on inland waterways and in ports and harbours,  except powered recreational craft as specified in the ISO 14509 series. This document is applicable to sea-going vessels, harbour vessels, dredgers, and all watercraft, including non-displacement craft, used  or capable of being used as a means of transport on water. There are no limitations to the application of this document with regard to speed, length and height of vessels, as long as the ship is determined to act like a point source at the reference distance of 25 m. All noise data obtained in accordance with this document are referred to a reference distance of 25 m.Frequency weighting A shall be used for all measurements. The time weighting shall be set to slow (S) for all measurements.  Care should be taken to avoid any influence on the result from unwanted sound signals, for example noise from the wind on the microphone of the measuring equipment, electrical interferences, or noise from extraneous sound sources not under consideration. If, in addition to the sound exposure level, spectral analysis in acceptance tests or determination of some special acoustical characteristics of vessels is needed, the quantities that shall be measured are the unweighted or C-frequency weighted, octave-band or one-third-octave-band S-time weighted sound pressure levels, in decibels, at the time of maximum sound pressure, or the unweighted or C-frequency weighted, octave-band or one-third-octave- band sound exposure levels, in decibels (dB). When measurements are made at some distance from the source, the levels observed can be considerably affected by the weather conditions. For example, the attenuation of sound due to air absorption is affected by the temperature and humidity of the air. In addition, the refraction of sound waves due to wind and temperature gradients affect the levels received at a particular position. It is recommended that measurements taken in extreme or atypical conditions be avoided. If possible, a value obtained under typical climatic conditions, and an indication of the range of values obtained under other  climatic conditions, should be included in the test report.BS EN ISO 2922 pdf download.