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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DAkkS D-ML-19082-01-00 Oberschleißheim, DE
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Echinococcus granulosus Echinococcus multilocularis Paragonimus uterobilateralis Ascaris lumbricoides (IgG) Brucella spp. (IgG, IgM) + 3 more
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Hämoglobin Differentialblutbild Erythrozyten Großes Blutbild Kleines Blutbild + 3 more
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Okkultes Blut Großes Blutbild Kleines Blutbild Retikulozyten Thrombozyten + 3 more
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2C-B 2C-I 3-Hydroxy-Bromazepam 5-Hydroxyindolessigsäure 6-Acetylcodein + 3 more
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Zelldifferenzierung Erythrozyten Großes Blutbild Hämoglobin Kleines Blutbild + 3 more
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Hämoglobin (immunologisch) CA 125 CA 15-3 CA 19-9 CA 72-4 + 3 more
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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
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DAkkS D-K-19788-01-00 Springe-Eldagsen, DE
Positiver und negativer verwendete Abkürzungen: DKD-R
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DAkkS D-PL-12084-01-00 Hamburg, DE
IEC 60945 IEC 61162-1 IEC 61162-2 IEC 61162-450 IEC 61162-460 + 3 more
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DAkkS D-K-15063-01-00 Berlin, DE
Radioaktivität 50 Bq/m³ Radon-222- 100 Bq/m³ tration in Luft 200 Bq/m³ + 3 more
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DAkkS D-PL-11075-01-01 Berlin, DE
DIN EN ISO 2808 DIN EN ISO 3219-2 DIN EN ISO 3838 DIN EN 933-1 DIN EN 933-4 + 3 more
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DAkkS D-K-11075-08-00 Berlin, DE
Conformity assessment — requirements for Railway composite brake blocks — require 0,2 kN 0,4 kN 100 kN + 3 more
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DAkkS D-ML-13381-01-01 Berlin, DE
NRBC-Normoblasten Anteil unreifer Retikulozyten Erythrozyten DELTA-He Leukozyten + 3 more
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DAkkS D-ML-13381-01-00 Berlin, DE
Blutungszeit PFA ADP Blutungszeit PFA EPI PFA-P2Y Erythrozyten Hämatokrit + 3 more
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DAkkS D-PL-12024-06-02 Nürnberg, DE
EN IEC 61000-4 DIN EN IEC 61000 VDE 0847-4 DIN EN 55016-2 DIN EN IEC 61000-6 + 3 more
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DAkkS D-K-20476-01-01 Dortmund, DE
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DAkkS D-K-20113-01-00 Wuppertal, DE
Charpy impact test (ISO 148-1) Salt spray / neutral salt fog test (ISO Radiated emissions (CISPR 32) verwendete Abkürzungen:
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DAkkS D-K-22378-01-01 Mühldorf a. Inn, DE
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DAkkS D-PL-11312-01-00 Nürnberg, 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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