Home

ISO 7235:2003
Subscribe to updates

Acoustics -- Laboratory measurement procedures for ducted silencers and air-terminal units -- Insertion loss, flow noise and total pressure loss

This standard has been reviewed* and then confirmed in 2013.

*ISO standards are reviewed every five years.

Abstract

ISO 7235:2003 specifies methods for determining

  • the insertion loss, in frequency bands, of ducted silencers with and without airflow,
  • the sound power level, in frequency bands, of the flow noise (or regenerated sound) generated by ducted silencers,
  • the total pressure loss of silencers with airflow, and
  • the transmission loss, in frequency bands, of air-terminal units.

The measurement procedures are intended for laboratory measurements at ambient temperature. Measurements on silencers in situ are specified in ISO 11820.

It is to be noted that the results determined in a laboratory according to ISO 7235:2003 will not necessarily be the same as those obtained in situ (installation), as different sound and flow fields will yield different results. For example, the pressure loss will be lower under laboratory conditions than in situ, but will be comparable between different laboratories.

ISO 7235:2003 is applicable to all types of silencer including silencers for ventilating and air-conditioning systems, air intake and exhaust of flue gases, and similar applications. Other passive air-handling devices, such as bends, air-terminal units or T-connectors, can also be tested using this International Standard.

It is not applicable to reactive silencers used for motor vehicles.

 

Related standards

Format
  • PDF

    This format preserves the paper layout, and is watermarked

  • EPUB

    This format allows documents to be read on tablets and smartphones

  • COLOUR PDF

    Enhanced user-friendly colour PDF format

  • PAPER

    Normally A4 size documents. Shipping costs apply

Language
PDF
Paper

Swiss francs CHF 158

Add to basket

Contact customer services

Send your enquiry by email
or call us on +41 22 749 08 88
09:00 – 12:30, 14:00 – 17:00 (UTC+1).