ISO 11820:2019

In-Situ Sound Attenuation Measurement of Silencers

ISO 11820 specifies the in-situ measurement method for determining the acoustic attenuation performance of silencers installed in railway ventilation ducts, brake systems, and exhaust lines. This test is critical for validating noise control equipment on operating trains and stationary installations where laboratory testing is impractical. Railway manufacturers, maintenance operators, and acoustic engineers use these measurements to verify compliance with noise regulations and to optimize silencer design. Accreditation ensures that attenuation claims are reliable and that performance targets for noise reduction are consistently achieved in real-world applications.

What it measures

  • Sound pressure level reduction across silencer (dB)
  • Attenuation performance by frequency band
  • Insertion loss of silencer in situ
  • Acoustic performance under operating conditions
  • Noise transmission loss through silencer element
🇩🇪 DIN EN ISO 11821 🇬🇧 BS EN ISO 11821 🇫🇷 NF EN ISO 11821 🇮🇹 UNI EN ISO 11821 🇪🇸 UNE EN ISO 11821 🇳🇱 NEN EN ISO 11821 🇩🇪 DIN EN ISO 3095 🇬🇧 BS EN ISO 3095 🇫🇷 NF EN ISO 3095 🇮🇹 UNI EN ISO 3095 🇪🇸 UNE EN ISO 3095 🇳🇱 NEN EN ISO 3095
1,273 Accredited labs
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LAYAKK SEGURIDAD INFORMÁTICA

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ENAC LE2494 Paterna, ES
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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
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LDH Kalibrierservice

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DAkkS D-K-18673-01-01 Dresden, DE
Gleichspannung 1 mV bis 10 mV Messgeräte > 10 mV bis 100 mV > 100 mV bis 220 mV > 220 mV bis 2,2 V > 2,2 V bis 11 V + 3 more
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LGAI TECHNOLOGICAL CENTER, S.A. (APPLUS+)

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ENAC LE894 Bellaterra, ES
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LINDE GAS ESPAÑA, S.A. (Unipersonal)

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ENAC LC10.040 Rubí, ES
10 · 10-6 mol/mol  C  20 · 10-6 mol/mo 10 · 10-6 mol/mol  C  5000 · 10-6 mol/ 1 · 10-6 mol/mol  C  10 · 10-6 mol/mol 1 · 10-6 mol/mol  C  5 · 10-6 mol/mol 10 · 10-6 mol/mol  C  100 · 10-6 mol/m + 3 more
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LNE - Laboratoires de Trappes

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COFRAC 1-0606 Trappes Cedex, FR
DIN EN ISO 2505 ISO 18553 AMD 1 DIN EN 12099 ISO 13480 ISO 6964 + 3 more
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LRQA Nederland

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RvA I081 Rotterdam, NL
NEN 3650-2 NEN 3650-1 NEN 3650-3 NEN 3651 NPR 3659
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Labor 28 MVZ

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Labor Brunner, Labormedizinisches Versorgungszentrum Konstanz

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LaborZentrum Weser Franz-Josef Schmitz

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DAkkS D-ML-13273-01-00 Minden, DE
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Industries

Railway rolling stock manufacturing Train maintenance and depot operations Acoustic engineering and noise control HVAC and ventilation system design Brake system suppliers and integrators

Related Standards

  • ISO 11821 Acoustics — In-situ measurement of sound insulation of windows and façades
  • EN ISO 3095 Acoustics — Measurement of noise emitted by railbound vehicles
  • ISO 7235 Acoustics — Laboratory measurement of sound absorption coefficient of materials in impedance tubes

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