ISO 13325:2019 pdf download

ISO 13325:2019 pdf download

ISO 13325:2019 pdf download.Tyres – Coast-by methods for measurement of tyre-to- road sound emission
1 Scope
This document specifies methods for measuring tyre -to-road sou nd emissions from tyres fitt ed on a motor vehicle under coast-by conditions, i.e. when the vehicle is in free-rolling, non-powered operation. This is typically achieved by putting the tra n smiss ion in the n eutral or equivalent position and switc hing off the engine as we ll as all auxiliary systems not necessary for safe driving. This document is applicable to passenger cars and commercial vehicles as defined in ISO 3833. It is not intended to be used to det ermine the sound contribution of tyres of vehicles running in power ed condition nor for the determination of traffic sound nuisance at a given location.
2 Normative references
The following documen ts are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 4223-1, of some terms used in the tyre industry – Part 1: Pneumatic tyres
ISO 10844, Acoustics – Specification of test tracks for measuring noise emitted by road vehicles and their tyres
IEC 60942, Electroacoustics – Sound
IEC 61672-1, Electroacoustic – Sound level meters – Part 1:
IEC 61672-3, Electroacoustic – Sound level meters – Part 3: Periodic tests
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 4223-1 apply.
ISO and IEC maintain terminological databases for use in standa rdization at the following addresses:
ISO Online browsing platform: available at
IEC Electropedia: available at
4 Symbols and abbreviated terms
4.1 The load index [ LI) is a numerical code associated with the maximum load a tyre can carry at the speed indicated by its speed symbol under the service conditions specified by the tyre manufacturer. In cases where the LI consists of two shall be made to the first number. F or tyres where the load index is not ava ilabl e, reference shall be made to the maximum load marked on the tyre sidewall.
7. 1 The sound pressur e level meter or equivalent measuring system, including the windscreen recommended by the microphone meet the minimum requirements of a Class 1 instrument in accordance with IEC 61672:-1 and/or IEC 61672-3. Alternatively, IEC 606511) may be used. The measurements shall be made using the frequency weighting, A, and the time weighting, F. The calibrat ion of the sound pressure level meter shall be checked and adjusted in accordance with the manufacturer ’ s instructions or with a standard sound source (e.g. piston phone) at the beginning of the measur eme nts and recheck ed and recorded at the end of them. Th e ca li bration device shall m eet the requirement s of Class 1 in accordance with IEC 60942. If the sound pressure level meter indications obtained from these calibrations differ by more than 0,5 dB during a series of measurements, the test shall be considered invalid. Any dev iation shall be recorded in the test report.