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
🇧🇪 NBN EN ISO 11821 🇩🇪 DIN EN ISO 11821 🇬🇧 BS EN ISO 11821 🇫🇷 NF EN ISO 11821 🇮🇹 UNI EN ISO 11821 🇪🇸 UNE EN ISO 11821 🇳🇱 NEN EN ISO 11821 🇧🇪 NBN EN ISO 3095 🇩🇪 DIN EN ISO 3095 🇬🇧 BS EN ISO 3095 🇫🇷 NF EN ISO 3095 🇮🇹 UNI EN ISO 3095
2,775 Accredited labs
21 Countries

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ift Rosenheim

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DAkkS D-PL-11349-01-01 Rosenheim, DE
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iki Institut für Krankenhaushygiene und Infektionskontrolle

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DAkkS D-PL-21129-01-03 Gießen, DE
10/1500 DIN EN ISO 19458 DIN EN ISO 10523 (C 5) DIN EN 27888 (C 8) DIN EN ISO 5667-3 (A 21) + 3 more
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imat-uve

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DAkkS D-PL-14052-01-01 Mönchengladbach, DE
Bauart wie GR 1482 17 I/D rs1799752 AK gegen BP 180 rs2066845 OMIM# 188400, 192430 + 3 more
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imetrologie GmbH Institut für Metrologie und Prozesstechnologie

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DAkkS D-K-15219-01-02 Helmstadt, DE
Vibration measuring instruments — test m Acoustics — tonality assessment (DIN 456 Whole-body vibration — evaluation of hum Railway braking — urban guided transport Railway vehicle body structural requirem + 3 more
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innomatec Mess- und Schnellanschluss-Systeme

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DAkkS D-K-19194-01-00 Idstein, DE
Railway brakes — disc brake pads (UIC 54 Railway pantographs — requirements for m abs > 2,0 bar Druck −1,0 bar + 3 more
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innomatec Mess- und Schnellanschluss-Systeme

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DAkkS D-K-19194-01-01 Idstein, DE
abs > 2,0 bar Druck −1,0 bar > 0,0 bar > 20 bar + 3 more
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iocto

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DAkkS D-K-21204-01-00 Hofheim am Taunus, DE
Railway braking — urban guided transport Railway braking — urban guided transport Railway vehicle body structural requirem abs direktanzeigende > 200 °C + 3 more
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labopart - Medizinische Laboratorien

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DAkkS D-ML-13309-01-00 Dresden, DE
Ethanol Absolutdruck Plasma, Serum, Plasma tration von Harnsäure tration von Harnstoff + 3 more
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Infektiologikum Fachärzte für Innere Medizin, Mikrobiologie, Virologie und Infektionsepidemiologie sowie Laboratoriumsmedizin

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Testosteron Folsäure Homocystein Thyroxin, freies (fT4) Urinsediment + 3 more
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mib Medizinisches Infektiologiezentrum Berlin

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muva kempten

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DAkkS D-PL-20469-01-01 Kempten, DE
DIN EN 15111 ISO 18787 DIN 10964 DIN EN ISO 4120 DIN EN ISO 6887-2 + 3 more
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qbig

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DAkkS D-K-21619-01-00 Leer, DE
Elektrische Messgrößen - Hochspannungsmessgrößen Volumendurchfluss − Hochspannungsmessgrößen Durchflussmess- 13 m³/h + 3 more
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seca

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DAkkS D-K-22590-02-01 Hamburg, DE
elektronische Waagen − Waagen nichtselbsttätige
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steep GmbH EMV-Zentrum

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DAkkS D-PL-12064-01-01 Bonn, DE
DIN EN 50155 VDE 0115-200 IEC 61000-4-2: 2008 IEC 61000-4-3: 2006 IEC 61000-4-4: 2012 + 3 more
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stichting star-shl

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RvA M025 Etten-Leur, NL
BS SOP004 using sandwich immunoassay Massaspectrometrie Bloedafname (extra-muraal) Chromatografie waaronder HPLC,UPLC,GC Semenanalyse incl. morfologie en motilit + 3 more
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synlab Medizinisches Versorgungszentrum Labor München Zentrum

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DAkkS D-ML-13149-01-00 München, DE
Antennenfaktor -regler mit einer > 0,03 L/min Aldosteron Cortisol Hydroxy-progesteron + 3 more
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tech-team Kalibrierlabor

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DAkkS D-K-15210-01-00 München, DE
- Gleichstromwiderstand 1) In den CMC sind die erweiterten Messu > 100 µA 330 V Wechselstromstärke 100 µA + 3 more
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velotech.de

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DAkkS D-PL-17439-02-00 Schweinfurt, DE
DIN EN 15194: 2018 DIN EN 15496 DIN EN 14619 DIN EN 15918 DIN 79008-1 + 3 more
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wbm Prüflabor

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DAkkS D-PL-11215-01-02 Eberswalde, DE
DIN EN 10160 DIN EN ISO 16810 DIN EN ISO 17637 DIN EN ISO 17638 DIN EN ISO 9934-1 + 3 more
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wfp Institut für Wellpappenforschung und -prüfung

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DAkkS D-PL-17881-01-01 Darmstadt, DE
HABP2-Gen (c.1601G>A) rs7080536 rs11887534 DIN EN ISO 16535 DIN EN 303-4 DIN EN 303-5 + 3 more
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ÖHMI Analytik

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DAkkS D-PL-14020-01-01 Magdeburg, DE
DIN EN 12879 DIN EN 12880 DIN EN ISO 19458 DIN EN ISO 11885 DIN EN ISO 10523 (C 5) + 3 more
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ÖP Öffentliche Prüfstelle für das Textilwesen der Hochschule Niederrhein

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DAkkS D-PL-19506-01-01 Mönchengladbach, DE
DIN EN 12681-1 ASTM D 3343 DIN EN 50491-5-1 DIN EN 1015-10 DIN EN 20105-A02 + 3 more
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Überörtliche Berufsausübungsgemeinschaft med. Uta Wisplinghoff und Kollegen und Medizinisches Versorgungszentrum für Humangenetik und Transfusionsmedizin Labor Wisplinghoff

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DAkkS D-ML-13062-01-01 Köln, DE
Railway running behaviour and bogies — t (ein- oder mehrgängige (DIN EN 61094-4:1996) Ethanol % (Hz) 0 | ± 1 + 3 more
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Überörtliche Berufsausübungsgemeinschaft Fachärzte für Laboratoriumsmedizin und Mikrobiologie

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DAkkS D-ML-19859-01-00 Bochum, DE
(ein- oder mehrgängige IRHD - L 10 IRHD-L % (Hz) 0 | ± 1 tration von Harnsäure tration von Harnstoff + 3 more
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Überörtliche Berufsausübungsgemeinschaft MVZ Eberhard & Partner Dortmund

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DAkkS D-ML-13403-01-00 Dortmund, DE
Absolutdruck tration von Harnsäure tration von Harnstoff pH - Wert homogene + 3 more
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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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