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 51–75 of 183 labs

ENAC LE1154 Boecillo, ES
UNE-EN ISO 16283-1 UNE-EN ISO 16283-2 UNE-EN ISO 16283-3 UNE-EN ISO 3382-2
View Profile

CIEMAT

Active
ENAC LE471 Madrid, ES
OM H-3 based on ISO 9698:2019 ISO 13164-4 SM 3111 UNE-EN ISO 13160 ISO 10704 + 3 more
View Profile
ENAC LE2543 Santa Cruz de Tenerife, ES
UNE-EN ISO 5667-19 UNE-EN ISO 16665 UNE-EN 19493
View Profile
ENAC LE1355 Carreño, ES
SM 2510 B SM 4500 H+ UNE 7027-1 UNE 7887 SM 4500-NO B 2 + 3 more
View Profile

INSST

Active
ENAC LE2151 Sevilla, ES
UNE-EN 136 UNE-EN 148-1 UNE-EN 140 UNE-EN 149 UNE-EN 13274-7 + 3 more
View Profile
ENAC LE2532 Viladecavalls, ES
UNE-EN 61000-4-2 UNE EN 61000-4-5 UNE-EN 55016-2-1 UNE-EN 61000-4-11 UNE-EN 61000-4-8 + 3 more
View Profile
ENAC LE2097 Castellón de la Plana, ES
UNE-EN ISO 140-5 UNE-EN ISO 16283-3 UNE-EN ISO 140-7 UNE-EN ISO 16283-1 UNE-EN ISO 140-4
View Profile
ENAC LE2384 Leganés, ES
ISO/IEC 15408-3 ISO/IEC 15408-1 ISO/IEC 15408-2 ISO/IEC 15408-4 ISO/IEC 15408-5 + 1 more
View Profile
ENAC LC10.255 Torrejón de Ardoz, ES
CEM EL-020 EURAMET cg-17 CEM EL CEM ME-004 EURAMET cg-11 + 3 more
View Profile
ENAC LE1009 Talayuela, ES
UNE 118019 UNE 118012 ISO 22980 UNE 118020 UNE 118021-2
View Profile
ENAC LE2170 Olot, ES
SM 3111 B SM 3500-K B SM 3500-Na B SM 2330 B SM 3113 B UNE-EN ISO 8467 + 3 more
View Profile
ENAC LE147 Campanillas, ES
IEC 61730-2 IEC 61215-1-2 IEC 61215-2 IEC 61215-1-3 IEC 61215-1-4 + 3 more
View Profile
ENAC LC10.204 Fuenlabrada, ES
0 mV  U < 330 mV 330 mV  U < 3,3 V 3,3 0 mV  U < 120 mV 120 mV  U < 1,2 V 1,2 0 A  I  330 A 330 A < I  3,3 mA 3, 20 A  I  1025 A 20 A  I  1025 A F = 50 Hz + 3 more
View Profile
ENAC LE776 Madrid, ES
SM 5210 D UNE-EN ISO 27888 SM 5220 D SM 2130 B UNE-EN ISO 11885 + 3 more
View Profile

DRACE GEOCISA

Active
ENAC LE334 San Fernando de Henares, ES
EPA 9056 ISO 13167 SM 3120 B ISO 13166 UNE 73350-1
View Profile
ENAC LC10.254 Sevilla, ES
50 ∙ 10-9 mol/mol ≤ C ≤ 237 · 10-9 mol/m 30∙ 10-9 mol/mol ≤ C ≤ 500 ∙ 10-9 mol/mo 50 ∙ 10-9 mol/mol ≤ C ≤ 1000 · 10-9 mol/ 50 ∙ 10-9 mol/mol ≤ C ≤ 237∙ 10-9 mol/mo 0,5 ∙ 10-9 mol/mol ≤ C ≤ 15 ∙ 10-9 mol/m + 1 more
View Profile
ENAC LE2175 Arroyo de la Encomienda, ES
UNE-EN ISO 16283-1 UNE-EN ISO 16283-3 UNE-EN ISO 16283-2 UNE-EN ISO 3382-1 UNE-EN ISO 3382-2
View Profile
ENAC LC10.206 Sant Cugat del Vallès, ES
200 kg/h ≤ m ≤ 60000 kg/h 200 l/h ≤ Q ≤ 60000 l/h 200 kg/h ≤ m ≤ 30000 kg/h 200 l/h ≤ Q ≤ 30000 l/h 700 Pa ≤ P ≤ 2 MPa + 3 more
View Profile
ENAC LE634 Navarrete, ES
UNE-EN 12211 UNE-EN 12210 UNE-EN 1026 UNE-EN 12207 UNE-EN 14608 + 3 more
View Profile
ENAC LE1999 San Sebastián de los Reyes, ES
Environmental noise — determination of s ISO 20906 : 2009-12 :
View Profile
ENAC LE1450 Basauri, ES
UNE-EN 12350-2 UNE-EN 12504-1 UNE-EN 12390-2 UNE-EN 12390-3 UNE-EN 12350-1 + 3 more
View Profile
ENAC LE2757 Madrid, ES
UNE-EN ISO 16283-1 UNE-EN ISO 16283-2 UNE-EN ISO 16283-3 UNE 74201 UNE-EN ISO 3382-2
View Profile
ENAC LE1853 Maliaño, ES
UNE-EN ISO 6892-1 DIN EN 10002-1 ASTM E 8 ASTM E 208 ASTM E208-06 + 3 more
View Profile
ENAC LE2182 Coslada, ES
UNE 64106 BS ISO 6731:2010 UNE-EN ISO 712 UNE-EN ISO 5534 ISO 13580 + 3 more
View Profile
ENAC LE709 Lorquí, ES
UNE EN ISO 15213-1 ISO 6888-1 ISO 7251 ISO 6888-3 ISO 4831 + 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