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
1,670 Accredited labs
18 Countries

Showing 1,051–1,075 of 1,670 labs

Microtech Services (Wessex)

Active
UKAS 1899 Bournemouth, GB
ISO 7251 # = 100 A ISO 6888-3 1) A:2b based on ISO 4833-2:2013 Amd 1:2 2) A:6c based on ISO 21528-1:2017 by mos + 1 more
View Profile

Mimete Srl Unipersonale

Active
ACCREDIA 01676 Biassono, IT
ASTM B212-21 ASTM E1019-24 ASTM B527-24 BS EN ISO 3923-1 ASTM B417-22 + 3 more
View Profile

Minebea Intec Bovenden

Active
DAkkS D-K-20451-01-00 Bovenden, DE
Konventioneller Wägewert/ Massenormale Charpy impact test (ISO 148-1) Salt spray / neutral salt fog test (ISO + 3 more
View Profile

Ministerium für Soziales, Gesundheit und Integration Baden-Württemberg Landesgesundheitsamt Baden-Württemberg

Active
DAkkS D-ML-19288-01-00 Stuttgart, DE
Bacillus cereus Toxin Clostridium perfringens Salmonella spp. Shigella spp. Staphylococcus aureus Toxin + 3 more
View Profile

Ministero della Difesa - Comando per le Operazioni in rete - Secure COR Lab

Active
ACCREDIA 02288 Roma, IT
ETSI EN 319 412 ETSI EN 319 401 ETSI EN 319 411-2 ETSI EN 319 411-1
View Profile

Mitie Environmental Services

Active
UKAS 0317 Derby, GB
(HSG 264, 2012) Appendix 5 of HSG 227 (2004))
View Profile

Mitutoyo Deutschland

Active
DAkkS D-K-15096-01-00 Neuss, DE
Parallelendmaße 0,5 mm DIN EN ISO 3650:1999 Parallelendmaße > 10 mm Parallelendmaße > 100 mm + 3 more
View Profile

Mobiler Kalibrierdienst Fini

Active
DAkkS D-K-21161-01-01 Esslingen, DE
Gleichspannung 3 mV Messgeräte 10 mV > 100 mV > 220 mV > 11 V + 3 more
View Profile

Moeller Operating Engineering

Active
DAkkS D-PL-12005-01-01 Itzehoe, DE
IEC 61000-4-7 IEC 61000-4-15 IEC 61000-4-30 IEC 61400-21 IEC 61400-21-1 + 3 more
View Profile

MonTech Werkstoffprüfmaschinen GmbH Kalibrierlabor

Active
DAkkS D-K-11292-01-00 Buchen Odenwald, DE
Temperatur 50 °C Railway brake handbooks (UIC 547) 1) In den CMC sind die erweiterten Messu
View Profile

Murrelektronik GmbH Prüfzentrum (4)

Active
DAkkS D-PL-19306-01-00 Oppenweiler, DE
IEC 61000-4-2: 2008 VDE 0847-4-2 IEC 61000-4-3: 2006 VDE 0847-4-3 IEC 61000-4-4: 2012 + 3 more
View Profile

Mühlenkreiskliniken AöR Institut für Laboratoriumsmedizin, Transfusionsmedizin und Mikrobiologie

Suspended
DAkkS D-ML-20225-01-00 Minden, DE
Differentialblutbild Kleines Blutbild (maschinell) Thrombozyten Unreife Thrombozyten (IPF) Urinsediment (maschinell) + 3 more
View Profile

Müller-BBM Building Solutions GmbH Akustisches Prüflaboratorium

Active
DAkkS D-PL-22339-02-01 Planegg, DE
DIN EN ISO 717-1 DIN EN ISO 717-2 DIN EN ISO 10140-2 DIN EN ISO 10140-4 DIN EN ISO 10140-5 + 3 more
View Profile

Müller-BBM Industry Solutions GmbH Kalibrierlaboratorium für Beschleunigung und akustische Messgrößen

Active
DAkkS D-K-14119-01-00 Planegg, DE
Pistonfonen und von Schallkalibratoren Pistonphonen und von (bezogen auf 20 µPa 31,5 Hz bis 16 kHz (bezogen auf 1 V/Pa) + 3 more
View Profile

Müller-BBM Industry Solutions GmbH Prüflaboratorium für Schall und Schwingungen, Elektromagnetische Felder und Licht, Immissionsschutz und Gefahrstoffe

Active
DAkkS D-PL-14119-01-01 Planegg, DE
DIN 4150-1 DIN 4150-2 DIN 4150-3 DIN ISO 8297 DIN EN ISO 12354-4 + 3 more
View Profile

München Klinik gGmbH Medizet - Institut für Laboratoriumsmedizin und medizinische Mikrobiologie

Active
DAkkS D-ML-13106-01-01 München, DE
Hämoglobin A1c Hämoglobin-Differenzierung Erythrozyten Basophile Granolozyten Eosinophile Granulozyten + 3 more
View Profile

N.V. Nederlandse Gasunie

Active
RvA I068 Groningen, NL
NEN 3650 NEN 1059 NEN 3656 NEN 3651 ISO 13480 + 2 more
View Profile

NATEC Sensors

Active
DAkkS D-K-15139-01-01 Garching, DE
Railway brakes — conditions for homologa − Durchfluss von Flüssigkeiten Gleichspannung U (Simulation des Signals generators) + 3 more
View Profile

NEOTES Ambiente e Qualità

Active
ACCREDIA 00846 Olevano sul Tusciano, IT
DIN EN 1186-3 DIN EN 17322 EPA 3535 BS EN 15662 EPA 3015 + 3 more
View Profile

NIPPON SANSO ESPAÑA, S.L. (Unipersonal)

Active
ENAC LC10.077 Madrid, ES
2 · 10–6 mol/mol  C  100 · 10–6 mol/mo 0,1 · 10–2 mol/mol < C  2,5 · 10–2 mol/ 1 · 10–6 mol/mol  C  100 · 10–6 mol/mo 5 · 10–6 mol/mol  C  20 · 10–6 mol/mol 0,15 · 10–2 mol/mol  C  20 · 10–2 mol/ + 3 more
View Profile

NMi TESTLAB

Active
DAkkS D-PL-17186-01-01 Blomberg, DE
IEC 61000-4-2: 2008 IEC 61000-4-3: 2006 IEC 61000-4-4: 2012 IEC 61000-4-5: 2005 IEC 61000-4-6: 2013 + 3 more
View Profile

NORMEC ABIOLAB

Active
COFRAC 1-7442 Montbonnot Saint Martin, FR
NF T 90-412 DIN EN ISO 7899-1 DIN EN ISO 10304-1 DIN EN ISO 6888-2 NF V08-054 + 3 more
View Profile

NORMEC QS

Active
RvA I248 Ede, NL
NEN-EN 13361 ISO 13362 NEN-EN 13491 DIN EN 13493 NEN-EN 13492 + 3 more
View Profile

NSF Wales Limited

Active
UKAS 0626 Newport, GB
BS EN ISO 7686:2005 DIN EN 997 DIN EN 13079 DIN ISO 10381-7 DIN EN 14622 + 3 more
View Profile

Narda Safety Test Solutions

Active
DAkkS D-K-17726-01-00 Pfullingen, DE
Elektrische Feldstärke / 2 V/m 2,5 V/m 1 V/m Magnetische Feldstärke / + 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