ISO 3744

Sound power — enveloping surface engineering method

ISO 3744 specifies the engineering method for determining sound power and sound energy levels using sound pressure measurements obtained on an imaginary surface (hemispherical or parallelepiped) surrounding a noise source. This method is widely used for in-situ testing of machinery, industrial equipment, and large installations where reverberation room testing is impractical. It provides a practical balance between accuracy and field applicability, making it suitable for machinery compliance testing, environmental noise assessments, and product CE marking requirements across the EU. ISO 17025 accreditation confirms laboratory proficiency in sound field measurement, environmental parameter correction, and uncertainty quantification for this complex measurement method.

What it measures

  • Sound power level (Lw) using enveloping surface pressure data
  • A-weighted and frequency-weighted sound power
  • Octave and one-third-octave band sound power (63 Hz to 8 kHz)
  • Environmental and measurement corrections
  • Sound power directivity and spatial variability
🇩🇪 DIN EN ISO 3740 🇬🇧 BS EN ISO 3740 🇫🇷 NF EN ISO 3740 🇮🇹 UNI EN ISO 3740 🇪🇸 UNE EN ISO 3740 🇳🇱 NEN EN ISO 3740 🇩🇪 DIN EN ISO 3743-1 🇬🇧 BS EN ISO 3743-1 🇫🇷 NF EN ISO 3743-1 🇮🇹 UNI EN ISO 3743-1 🇪🇸 UNE EN ISO 3743-1 🇳🇱 NEN EN ISO 3743-1
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UKAS 0131 South Wirral, GB
Joint IP/ASTM methods marked IP 195*ASTM D1078 ASTM D847 by titration ASTM D848 ASTM D 1353 + 3 more
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UKAS 0244 Broadlands, GB
(HSG 248) – 2021 ASB/SOP/OM8 based on HSG 248 (PCM) based on HSG 248
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UKAS 4412 Colbourne Crescent, GB
CHEM014 based on BS 4401 based on BS 4401 Part 4:1970 CHEM018 based on BS 4401 CHEM023 based on BS 4401- ISO 6579-1 + 3 more
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SGS United Kingdom

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UKAS 1549 Bar Hill, GB
Method CBG-M-SOP-027 based on BS EN ISO AM01 based on BS EN ISO 4833-1: 2) Method CBG-M-SOP-038 based on BS ISO ISO 10272-2 Method CBG-M-SOP-007 based on BS EN ISO + 3 more
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SGS United Kingdom

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UKAS 0820 South Wirral, GB
MPV Thrombozytenvolume Gas meters Power meter method LENGTH Waterdraw Method + 3 more
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UKAS 0032 Oldbury, GB
BS EN 286 - Simple unfired pressure BS EN 13445 Unfired pressure BS EN13480 Metallic industrial BS EN 12953 Shell boilers BS EN BS EN 12952 Water-tube + 3 more
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SGS United Kingdom

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UKAS 2001 Whetstone, GB
ISO 14184-1 ISO 14184-2 BS EN ISO 1833-1:2020 BS EN ISO 105-B02:2014 BS 4407 + 3 more
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SML Laboratories

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UKAS 31703 Eastbourne, GB
Surveying) based on HSG 248
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SOCOTEC Asbestos

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UKAS 1089 Burton-on-Trent, GB
(HSG 248) – 2021 SCI/ASB/003 based on HSG 248 (PCM) based on HSG 248 SCI/ASB/001 based on HSG 248
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SOCOTEC Asbestos

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UKAS 0148 Burton-upon-Trent, GB
(HSG 264, 2012) 5 of HSG 227 (2004)
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SOCOTEC UK

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UKAS 1015 Burton-upon-Trent, GB
DIN EN 13284-1 ENV/054 based on BS EN ISO 11731 DIN EN 14791 IEC 60519-11 + 3 more
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Safe Gas Cylinders

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UKAS 4430 Swansea, GB
BS EN 1440:2016 + A1:2018 + EN ISO 23088:2020 Cylinders EN ISO 10460:2018 EN 14208:2004
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Safety Advice Centre

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UKAS 4103 Bangor, GB
M002based on HSG 248 (HSG 248) – 2021 (PCM) based on HSG 248
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Scientific Electro Systems

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UKAS 0772 Rochford, GB
TORQUE increasing torque only.
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Scientific Services

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UKAS 2577 Redruth, GB
(HSG 248) – 2021 D3TA2 based on HSG 248 (PCM) based on HSG 248 D3TA8 based on HSG 248
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Scope iT

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UKAS 9086 Manchester, GB
Appendix 5 of HSG 227 (2004)) (HSG 264, 2012)
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Scopus Asbestos Compliance

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UKAS 10483 Ossett, GB
(HSG 248) – 2021 SAC-SOP-15 based on HSG 248 SAC-SOP-07 based on HSG 248 staining based on HSG 248
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SembCorp Utilities (UK)

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UKAS 2210 Wilton International, GB
(HSG 248) – 2021 DI/AN/ME/025 based on HSG 248 DI/AN/ME/001 based on HSG 248 DI/AN/ME/026 based on HSG 248 (PCM) based on HSG 248
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ServiceCal

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UKAS 0152 Heywood, GB
PRESSURE (cont’d) DC CURRENT DC VOLTAGE CFH-Gen, Macula-Degeneration Measurement + 3 more
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Sharps Redmore Partnership

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UKAS 2809 Copdock, GB
BS EN ISO 16283-1:2014+A1:2017BS EN ISO BS EN ISO 16283-2:2020 BS EN ISO 140-4:1998 BS EN ISO 717-2:2020 ISO 1407 + 1 more
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Sheffield Calibration Services

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UKAS 9157 Sheffield, GB
LENGTH Plain plug gauges (parallel) Internal Caliper LENGTH (cont’d) + 3 more
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Shirley Technologies

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UKAS 1066 Leeds, GB
ASTM E 2149-20 BS EN ISO 20743:2021 Section ISO 14119 BS EN ISO 20645:2004 BS 1425-1:1991 Appendix A + 3 more
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Sigma-HSE (UK)

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UKAS 9248 Winall, GB
DIN EN 13821 Sigma-HSE (UK) Ltd DIN EN 14034-1 BS EN ISO/IEC 80079-20-2:2016 DIN EN 14034-2 + 3 more
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Somerset Council

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UKAS 0369 Wellington, GB
(HSG 248) – 2021 R24 based on HSG 248 staining based on HSG 248
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Sound Solution Consultants

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UKAS 4686 Ipswich, GB
BS EN ISO 16283-1:2014+A1:2017BS EN ISO BS EN ISO 16283-2:2020 BS EN ISO 140-4:1998 BS EN ISO 717-2:2020 ISO 1407 + 1 more
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Industries

Industrial machinery manufacturers Construction equipment producers HVAC and ventilation systems Power generation and compressor suppliers Large transport and handling equipment makers

Related Standards

  • ISO 3740 Acoustics — Determination of sound power levels of noise sources — General guidelines
  • ISO 3743-1 Acoustics — Determination of sound power levels of noise sources — Part 1: Reverberation room method
  • ISO 3745 Acoustics — Determination of sound power levels of noise sources — Precision method using an enveloping surface

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