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
1,516 Accredited labs
17 Countries

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COFRAC 1-0064 Saint-Marcel, FR
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ENAC LC10.255 Torrejón de Ardoz, ES
CEM EL-020 EURAMET cg-17 CEM EL CEM ME-004 EURAMET cg-11 + 3 more
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ENAC LE1009 Talayuela, ES
UNE 118019 UNE 118012 ISO 22980 UNE 118020 UNE 118021-2
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- Gleichspannung Quellen > 0,10 V > 1 V > 10 V - Gleichstromstärke + 3 more
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SM 3111 B SM 3500-K B SM 3500-Na B SM 2330 B SM 3113 B UNE-EN ISO 8467 + 3 more
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ACCREDIA 00215 Montelabbate, IT
ISO 16000-3 BS ISO 9227:2022 ISO 16000-6 ISO 16000-9 DIN EN 14749 + 3 more
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COFRAC 1-0097 Charleville-Mezieres, FR
DIN EN ISO 6508-1 ASTM E8/E 8M DIN EN ISO 643 EN ISO 12624 ISO 4967 + 3 more
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ACCREDIA 00841 Grugliasco, IT
EN ISO 16119-2 DIN EN ISO 28139 EN ISO 16119-3 EN ISO 19932-1 EN ISO 19932-2
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DAkkS D-PL-12030-01-02 Plattling, DE
DIN EN 55016-2 VDE 0877-16-2-1 VDE 0877-16-2-2 VDE 0877-16-2-3 EN IEC 61000-4 + 3 more
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ACCREDIA 00009 Bollate, IT
BS 1363-1 BS EN 15662 DIN EN ISO 6888-1 DIN EN 60068-2-30 DIN EN 81-58 + 3 more
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COFRAC 1-0300 Marne La Vallee Cedex 2, FR
DIN EN 947 DIN CEN TS 15119-2 NF P 20-501 DIN EN 1026 BS EN 14351-1:2006+A2:2016 + 3 more
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COFRAC 1-1542 Saint Martin D'Heres, FR
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UKAS 0654 Norwich, GB
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UKAS 0789 Great Dunmow, GB
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UKAS 1079 Gloucestershire, GB
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DAkkS D-PL-12125-01-01 Oberkochen, DE
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DAkkS D-K-21703-01-00 Oberkochen, DE
Carl Zeiss Industrielle ≤ 3818 mm Oberkochen, D 1) In den CMC sind die erweiterten Messu Carl Zeiss Industrielle ≤ 20 m Auswertesoftware Messvolumen mit + 3 more
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DAkkS D-PL-12037-01-02 Jena, DE
DIN EN 61010-1 VDE 0411-1 IEC 61010-1 : 2010 DIN EN 60825-1 VDE 0837 + 3 more
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DAkkS D-K-12037-01-01 Jena, DE
Parallelendmaße * 0,5 mm DIN EN ISO 3650:1999 Parallelendmaße * 40 mm Parallelendmaße * ≥ 100 mm Strichmaßstäbe 0 mm + 3 more
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UKAS 27202 Paisley, GB
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UKAS 7914 Willsbridge, GB
5 of HSG 227 (2004)) (HSG 264, 2012)
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UKAS 1643 Chelmsford, GB
(cdt), Deletion an Pos 117 (HSG 248) – 2021 (PCM) based on HSG 248 BS 6068-4.12:1998 (withdrawn)
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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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