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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DIN EN 12209 DIN EN 1155 DIN EN 12179 DIN EN 1935 DIN EN 1670 + 3 more
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IEC 61851-1: 2010 IEC 61851-23 IEC 62109-1 IEC 62109-2 IEC 61010 + 3 more
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ACCREDIA 00999 Carugate, IT
DIN EN 60068-2-30 IEC 61000-6-1 AS/NZS CISPR 22:2006 IEC 61000-6-2: 2005 ETSI EN 303 446-2 + 3 more
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UKAS 0224 Finchampstead, GB
(HSG 264, 2012) and Appx. 3 of HSG 227 (2004)) guides HSG 264 (2012) and ACoP L8 and BS 8580-1:2019
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ENAC LC10.082 Legutiano, ES
CEM DI-007 CEM DI-021 CEM DI-004 CEM DI-018 CEM DI-002 + 3 more
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URIKER

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UNE 77061 SM 4500-NO-3 E UNE-EN ISO 7027-1 ISO 15923-1 UNE-EN ISO 7393-2 + 3 more
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DIN EN 12667 ISO 8301 DIN EN 12939 DIN EN 12664 DIN EN ISO 13163 + 3 more
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Pistonphones Microphones LS2/WS2 microphones based: Reverberation Time
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UKAS 1262 Salford, GB
BS EN ISO 10140-2:2021 DIN EN ISO 11654 ISO 354 ISO 7171 ASTM E90-09(2016) + 3 more
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Universität Regensburg Institut für Humangenetik

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Universität Stuttgart Institut für Gebäudeenergetik, Thermotechnik und Energiespeicherung

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DIN EN 442-2 DIN EN 16430-1 DIN EN 16430-2 DIN EN 16430-3 DIN 4703-3 + 3 more
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Universität Stuttgart Materialprüfungsanstalt

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DAkkS D-K-11027-01-02 Stuttgart, DE
Sound power — engineering method using a Sound power — survey method (ISO 3746) Sound power — in-situ using reference so Sound intensity — scanning method (ISO 9 Sound intensity — scanning method part 2 + 3 more
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Universität Stuttgart Materialprüfungsanstalt Universität Stuttgart

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DIN EN ISO 4590 DIN EN ISO 9053-1 DIN EN ISO 12571 DIN EN ISO 12572 DIN EN ISO 15148 + 3 more
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Universitätsklinikum Aachen AöR (Uniklinik RWTH Aachen) Labordiagnostisches Zentrum

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(Long Read): SNV, CNV, Repeats FMR1-Gen (fraX, POF, FXTAS) Charcot-Marie-Tooth-Erkrankung Cardiolipin (CMT) GARS1, GDAP1, GJB1, HSPB1, IGHMBP2, LITA + 3 more
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Universitätsklinikum Aachen AöR (Uniklinik RWTH Aachen) lnstitut für Transfusionsmedizin und Zelltherapeutika

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Universitätsklinikum Bonn Institut für Klinische Chemie und Klinische Pharmakologie - Zentrallabor

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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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