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
1,868 Accredited labs
20 Countries

Showing 701–725 of 1,868 labs

Home Counties Asbestos

Active
UKAS 24561 Hertford, GB
(HSG 264, 2012)
View Profile

Hoppesack Mess- und Regeltechnik Vertriebs

Active
DAkkS D-K-15198-01-00 Hanau, DE
Taupunkttemperatur thermometer, -80 °C bis Railway braking — urban guided transport > -35 °C bis Temperatur- −35 °C bis + 3 more
View Profile

Horiba Europe

Active
DAkkS D-K-12094-02-00 Oberusel, DE
0,6 bar ver Überdruck p e * Absolutdruck p abs 100 mbar > 70 mbar Gaskonzentration + 3 more
View Profile

Horiba Europe GmbH Labor für Fahrzeugprüftechnik

Active
DAkkS D-K-12094-01-02 Darmstadt, DE
–1 bar Positiver und negativer Positiver Überdruck p e > 0,0 bar Absolutdruck p abs 0,25 bar + 3 more
View Profile

Hottinger Brüel & Kjaer

Active
DAkkS D-K-12029-02-02 Darmstadt, DE
Übertragungsmaß von Messmikrofonen oder Freifeld-Leerlauf- 20 Hz Freifeld -Übertragungsmaß Vorverstärker, nach IEC + 3 more
View Profile

HyGES, Gesellschaft für Hygieneberatung und -analytik

Active
DAkkS D-PL-13181-01-01 Mönchengladbach, DE
DIN ISO 5667-5 (A 14) DIN EN ISO 19458 (K 19) DIN 19643-1 DIN EN ISO 7887 (C 1) DIN 38404-C 4 + 3 more
View Profile

Hydrodata

Active
DAkkS D-PL-18139-01-00 Oberursel, DE
DIN EN ISO 5667-1 (A 4) DIN 38402-A 12 DIN 38402-A 13 DIN 38402-A 15 DIN EN ISO 5667-3 (A 21) + 3 more
View Profile

Hydrotechnik

Active
DAkkS D-K-15045-01-01 Limburg a. d. Lahn, DE
Negativer und Positiver Überdruck p e > 0,015 bar Überdruck p (ein- oder mehrgängige + 3 more
View Profile

HygCen Germany

Active
DAkkS D-PL-18818-02-02 Schwerin, DE
DIN EN ISO 10993-1 DIN EN ISO 10993-5 DIN EN ISO 17405 ISO 10993-23 DIN EN ISO 10993-18 + 3 more
View Profile

Hygiene Nord

Active
DAkkS D-PL-18411-01-04 Greifswald, DE
DIN EN ISO 10993-5 DIN EN ISO 10993-1 DIN EN ISO 11737-2 DIN EN 1040 DIN EN IEC 60601-2-75 + 3 more
View Profile

Hygiene-Institut AYSID

Active
DAkkS D-PL-18628-02-00 Berlin, DE
DIN 1946-4 DIN EN 13098 DIN EN ISO 17141 ISO 14644-3 DIN 12980 + 1 more
View Profile

Häfner Gewichte GmbH MASSCAL - Kalibrierlaboratorium

Active
DAkkS D-K-15192-01-00 Oberrot, DE
Innen- und Tiefenmaße Konventioneller Wägewert/ Massenormale Festkörpervolumen + 3 more
View Profile

I17-Wind

Active
DAkkS D-PL-21268-01-00 Husum, DE
ISO 9613-2
View Profile

I2 Analytical

Active
UKAS 4041 Croxley Green, GB
staining based on HSG 248. (HSG 248) – 2021 (PCM) based on HSG 248 A007B based on BS EN15051-2:2013 +1:2016 DIN EN 12457-3 + 3 more
View Profile

IANESCO

Active
COFRAC 1-6209 Poitiers, FR
DIN EN ISO 17294-2 ISO 7086-2:2000 DIN EN ISO 14403-2 DIN EN ISO 13395 NF T 90-412 + 3 more
View Profile

IBAS Ingenieurgesellschaft für Bauphysik, Akustik und Schwingungstechnik

Active
DAkkS D-PL-20737-01-00 Bayreuth, DE
DIN 4150-1 DIN 4150-2 DIN 4150-3 DIN EN 61800-5-1: 2017
View Profile

ICAR-CM2T

Active
COFRAC 1-1483 Moncel-Les-Luneville, FR
NF EN ISO 1927-3 NF EN ISO 1927-5 ASTM C 862 ASTM C 865 (DIN EN 61094-4:1996) + 3 more
View Profile

IDIADA AUTOMOTIVE TECHNOLOGY

Active
ENAC LE159 Santa Oliva, ES
DIN EN 1385 EN 17092-1:2020 DIN EN ISO 5077 EN 1317-1 DIN EN ISO 13688 + 3 more
View Profile

IEL

Active
DAkkS D-PL-11011-01-02 Aurich, DE
DIN 45691
View Profile

IFB Eigenschenk

Active
DAkkS D-PL-19746-01-04 Deggendorf, DE
DIN EN ISO 17892-2 DIN EN ISO 17892-3 DIN EN ISO 17892-4 DIN 18121-2 DIN 18125-2 + 3 more
View Profile

IFF Engineering und Consulting

Active
DAkkS D-K-11332-01-02 Leipzig, DE
Kraft 10 kN Sound power — survey method (ISO 3746) Radaufstandskraft- 10 kN Prüfkraftmesseinrichtung Länge 10 mm
View Profile

IFL Institut für Lärmschutz

Active
DAkkS D-PL-20186-01-00 Düsseldorf, DE
DIN EN 61800-5-1: 2017
View Profile

IFLb Laboratoriumsmedizin Berlin GmbH MVZ IFLb - Institut für Laboratoriumsmedizin Berlin

Active
DAkkS D-ML-13224-01-01 Berlin, DE
HbA1c Vitamin A Vitamin B1 Vitamin B2 Vitamin B6 + 3 more
View Profile

IFTS

Active
COFRAC 1-0847 Foulayronnes, FR
NF X 45-301 NF X 45-302 NF X 45-303 ASTM F795-88 NF P 90-319 de 02/2011 + 3 more
View Profile

IGIENAIR LORRAINE

Active
COFRAC 1-6747 Atton, FR
NF EN 12469 Annexe G NF S 90-351 NF EN 12469 Annexe D NF X 15-206 DIN EN 14175-4 + 3 more
View Profile

No matching labs found.

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

Other Test Methods

0 labs selected
Compare