ISO 3744

Sound power โ€” 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
๐Ÿ‡ฉ๐Ÿ‡ช DIN EN ISO 3740 ๐Ÿ‡ฌ๐Ÿ‡ง BS EN ISO 3740 ๐Ÿ‡ซ๐Ÿ‡ท NF EN ISO 3740 ๐Ÿ‡ฎ๐Ÿ‡น UNI EN ISO 3740 ๐Ÿ‡ช๐Ÿ‡ธ UNE EN ISO 3740 ๐Ÿ‡ณ๐Ÿ‡ฑ NEN EN ISO 3740 ๐Ÿ‡ฉ๐Ÿ‡ช DIN EN ISO 3743-1 ๐Ÿ‡ฌ๐Ÿ‡ง BS EN ISO 3743-1 ๐Ÿ‡ซ๐Ÿ‡ท NF EN ISO 3743-1 ๐Ÿ‡ฎ๐Ÿ‡น UNI EN ISO 3743-1 ๐Ÿ‡ช๐Ÿ‡ธ UNE EN ISO 3743-1 ๐Ÿ‡ณ๐Ÿ‡ฑ NEN EN ISO 3743-1
1,868 Accredited labs
20 Countries

Showing 151โ€“175 of 254 labs

COFRAC 1-0833 Mende, FR
DIN EN ISO 17294-2 DIN EN ISO 14403-2 NF T 90-412 DIN EN ISO 21528-2 DIN EN ISO 7899-1 + 3 more
View Profile
COFRAC 1-1466 Pessac Cedex, FR
NF V08-106 NF T 90-412 NF EN ISO 7887 โ€“ VDE 414-9-11 DIN EN ISO 7899-1 + 3 more
View Profile
COFRAC 1-0551 Laon Cedex, FR
DIN ISO 11466 NF X31-120 DIN EN ISO 11885 NF X31-147 DIN EN 16175-1 + 3 more
View Profile
COFRAC 1-0796 Dijon Cedex, FR
DIN EN ISO 17294-2 DIN EN ISO 14403-2 DIN EN ISO 13395 NF T 90-412 DIN EN ISO 7899-1 + 3 more
View Profile
COFRAC 1-7330 Montauban, FR
DIN EN ISO 10703 NF T 90-412 DIN EN ISO 21528-1 DIN EN ISO 7899-1 VDE 414-9-11 + 3 more
View Profile
COFRAC 1-0977 Montpellier Cedex 2, FR
DIN EN ISO 13395 DIN EN ISO 7899-1 DIN EN ISO 6888-2 ISO 5815-1 NF T90-015-1 + 3 more
View Profile
COFRAC 1-0997 Limoges, FR
ISO 5815-1 EN 13087-2 DIN EN ISO 6579-1 NF U47-108 ISO 15705 + 3 more
View Profile
COFRAC 1-1046 Les Ponts De Ce, FR
NF V08-401 DIN EN ISO 6888-2 DIN ISO 16649-2 BS ISO 15214:1998 NF V08-409 + 3 more
View Profile
COFRAC 1-1356 Gap Cedex, FR
NF V 04-155 DIN EN ISO 21528-2 DIN ISO 16649-2 DIN EN ISO 6888-2 NF V08-054 + 3 more
View Profile
COFRAC 1-1105 Serres-Castet, FR
DIN EN 10002-1 ASTM E8/E 8M ASTM A 370 NF EN ISO 6892-1 (mรฉthodes A1, A2 et DIN EN 2002-001 + 3 more
View Profile
COFRAC 1-1021 Saint Beauzire, FR
ISO 14698-1 DIN EN ISO 17141 DIN EN 12469 DIN EN ISO 11138-2 DIN EN ISO 11737-2 + 3 more
View Profile
COFRAC 1-6990 La Ciotat, FR
DIN EN 13624 DIN EN 13727 DIN EN ISO 11930 DIN EN 17387 DIN EN ISO 22717 + 3 more
View Profile
COFRAC 1-1979 Limoges, FR
NF V 04-407 DIN EN ISO 6888-1 NF V04-403 0.95) based on BS ISO 21527-2:2008 DIN EN ISO 6888-2 + 3 more
View Profile
COFRAC 1-1160 Trinite, FR
NF T 90-412 DIN EN ISO 6888-1 DIN EN ISO 7899-1 DIN EN ISO 21528-2 DIN ISO 16649-2 + 3 more
View Profile
COFRAC 1-0714 Sophia Antipolis Cedex, FR
DIN EN ISO 21528-2 DIN EN ISO 6888-2 DIN ISO 16649-2 ISO 5815-1 BS ISO 15214:1998 + 3 more
View Profile
COFRAC 1-1173 Lagor, FR
DIN EN 14385 NF U47-002 NF X43-551 ETSI EN 301 489-1 V2.2.3 2019-11 DIN EN ISO 14403-2 + 3 more
View Profile
COFRAC 1-1847 Lyon 7Eme, FR
DIN EN 10002-1 BS ISO 9227:2022 DIN EN ISO 643 EN ISO 12624 DIN EN 10045-1 + 3 more
View Profile

LABSUD7

Active
COFRAC 1-7045 Sete, FR
NF X 43-050 (parties utiles NF X 43-269 NF X 43-050
View Profile
COFRAC 1-1734 La Capelle, FR
DIN EN ISO 8968-1 DIN 19662 DIN EN ISO 5534 DIN EN ISO 8968-4 DIN EN ISO 5764 + 3 more
View Profile

LDA 13

Active
COFRAC 1-1290 Marseille Cedex 13, FR
NF V08-106 DIN EN ISO 17294-2 NF T 90-412 NF U47-105 DIN EN ISO 7899-1 + 3 more
View Profile
COFRAC 1-2193 Bourg-En-Bresse Cedex 9, FR
DIN EN ISO 17604 NF V08-401 0.95) based on BS ISO 21527-2:2008 DIN EN ISO 6888-2 DIN ISO 16649-2 + 3 more
View Profile

LDAE 95

Active
COFRAC 1-1405 Cergy, FR
NF T 90-412 DIN EN ISO 7899-1 VDE 414-9-11 DIN EN ISO 10304-1 ISO 5815-1 + 3 more
View Profile
COFRAC 1-2350 Villepinte, FR
NF X 43-269 DIN 51750-3 NF X 46-032 NF EN 15934 โ€“ NF X 43-269 โ€“ Annexe K + 3 more
View Profile

LHEM

Active
COFRAC 1-0053 Gonfreville L'Orcher, FR
NF EN ISO 6892-1 Mรฉthode B DIN EN ISO 6508-1 ISO 4969 DIN EN 10002-1 DIN EN ISO 643 + 3 more
View Profile

LIDAL

Active
COFRAC 1-0600 Annecy, FR
NF T 90-412 DIN EN ISO 7899-1 DIN EN ISO 10304-1 DIN EN ISO 6888-2 DIN ISO 16649-2 + 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 โ€” Determination of sound power levels of noise sources โ€” General guidelines
  • ISO 3743-1 Acoustics โ€” Determination of sound power levels of noise sources โ€” Part 1: Reverberation room method
  • ISO 3745 Acoustics โ€” Determination of sound power levels of noise sources โ€” Precision method using an enveloping surface

Other Test Methods

0 labs selected
Compare