Akustikk og akustiske målinger

Komité: CEN/TC 256 (Railway applications)
Opprinnelse: SN
Sluttdato: 23. feb 2023
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The standard addresses the measurement of source terms for environmental noise calculation for rail traffic (including light rail). It is applicable to the measurement of in-service trains on operational tracks. It is not applicable to type acceptance testing of rolling-stock or tracks. The following rail traffic noise sources are in the scope: - Rolling noise ; - Traction noise ; - Aerodynamic noise ; - Impact noise (e.g. rail joints, switch & crossings, wheel flats) ; - Bridge noise ; - Squeal noise. Noise from rail vehicles at standstill is included e.g.: engine idling and auxiliary equipment. Noise from fixed installations (e.g.: stations, depots, electricity sub-stations) are not in the scope of this standard. Each source shall individually be characterized in terms of its frequency spectrum (up to one-third octave band details), source height and directivity. Rolling noise will then be described in terms of its generating wheel and rail roughness along with the vehicle and track transfer functions. Source terms will be specific to a vehicle and track type. The scope includes measurement procedures and conditions and sampling requirements.
Komité: ISO/TC 43/SC 1 (Noise)
Opprinnelse: SN
Sluttdato: 16. mar 2023
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This document gives guidance on the determination of (measurement) uncertainties of sound power levels determined according to ISO 3741, ISO 3743-1, ISO 3743-2, ISO 3744, ISO 3745, ISO 3746 and ISO 3747
Komité: ISO/TC 43/SC 1 (Noise)
Opprinnelse: ISO
Sluttdato: 17. mar 2023
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This document specifies methods for qualifying an environment that approximates to an acoustic free field near one or more reflecting planes. The goal of the qualification is to determine the environmental correction K2, which is used to correct for reflected sound when determining the sound power level or sound energy level of a noise source from sound pressure levels measured on a surface enveloping the noise source (machinery or equipment) in such an environment. In addition, the environmental correction K2  is used as an input parameter for the determination of the local environmental correction K3 which is used to determine the emission sound pressure level in an environment that approximates to an acoustic free field near one or more reflecting planes.


In practice, the K2  value determined will be a function of both the reflected sound from the test environment and the shape and size of the measurement surface used for the K2 determination. For the purposes of this standard and the standards that refer to it, the differences between K2  values determined with different measurement surfaces are assumed to be included in the stated measurement uncertainty for the test method.

Komité: ISO/TC 43/SC 1 (Noise)
Opprinnelse: SN
Sluttdato: 17. mar 2023
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This document specifies methods for qualifying an environment that approximates to an acoustic free field near one or more reflecting planes. The goal of the qualification is to determine the environmental correction K2, which is used to correct for reflected sound when determining the sound power level or sound energy level of a noise source from sound pressure levels measured on a surface enveloping the noise source (machinery or equipment) in such an environment. In addition, the environmental correction K2  is used as an input parameter for the determination of the local environmental correction K3 which is used to determine the emission sound pressure level in an environment that approximates to an acoustic free field near one or more reflecting planes. In practice, the K2  value determined will be a function of both the reflected sound from the test environment and the shape and size of the measurement surface used for the K2 determination. For the purposes of this standard and the standards that refer to it, the differences between K2  values determined with different measurement surfaces are assumed to be included in the stated measurement uncertainty for the test method.