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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Münchingen, D CAM 2, Software von Holos, Software von Carl Metrologic, Software von Metrologic Group ≤ 9090 mm + 3 more
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8tree GmbH 8tree Calibration Lab

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8tree Scanner / 0 mm bis 100 mm Laterale Größe von Tiefenmaß/ -unterstand (Härteskalen HV0,01
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Kraft 0,5 N Zug- und Druckkraft Vibration measuring instruments — requir Sound power — in-situ using reference so 20 kN + 3 more
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ABB AG Kalibrierlaboratorium für Druck, Durchfluss und Temperatur

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DAkkS D-PL-14560-01-02 Potsdam, DE
BS EN ISO 16283-1:2014+A1:2017BS EN ISO ISO 10052 BS EN ISO 16283-2:2020 DIN EN ISO 16283-3 DIN 4109-4
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DAkkS D-PL-18883-01-00 Berlin, DE
DIN ISO 16000-3 DIN ISO 16000-6 DIN EN ISO 16017-1 DIN ISO 12884 EN 16516 + 3 more
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DAkkS D-PL-14162-01-03 Altenberge, DE
DIN EN ISO 15587-1 DIN EN ISO 15587-2 DIN EN ISO 14403-2 DIN 38405-4 DIN 38405-8 + 3 more
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AMETEK CTS Europe GmbH Kalibrierlabor

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DAkkS D-K-15033-01-00 Berlin, DE
1,5 V/m bis 30 V/m 3 V/m bis 100 V/m 1 GHz bis 8 > 8 GHz bis 18 - Gleichspannung + 3 more
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DAkkS D-K-15060-01-00 Dettingen unter Teck, DE
Messschieber für 0 mm Außen-, Innen- und > 500 mm > 1000 mm Tiefenmessschieber * 0 mm Sondermessschieber 0 mm + 3 more
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Ahlborn Meß- und Regelungstechnik

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DAkkS D-K-19342-01-02 Holzkirchen, DE
Taupunkttemperatur Railway braking — urban guided transport Temperaturtransmitter Widerstandssensor *) –30 °C + 3 more
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Airbus Defence and Space

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DAkkS D-K-18731-01-01 Manching, DE
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EN 14033-3 ISO 9611 ISO 11201
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DAkkS D-PL-20065-01-00 Potsdam, DE
DIN 4150-1 DIN 4150-2 DIN 4150-3 DIN EN 61400-11
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DAkkS D-PL-18995-01-00 Göttingen, DE
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Akustikbüro K5

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DAkkS D-PL-20822-01-00 Berlin, DE
DIN EN IEC 60268-16 DIN VDE 0833-4
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Akustikbüro Krämer & Stegmaier

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ISO 23351-1 ASTM E 1354 DIN EN ISO 717-1 DIN EN ISO 717-2 DIN EN ISO 3382-1 + 3 more
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Allgäuer Messzentrum

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DAkkS D-K-19562-01-01 Kaufbeuren, DE
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Ambulanzzentrum des UKE GmbH Fachbereich Labormedizin

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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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