Scope
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
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DIN EN ISO 11821
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BS EN ISO 11821
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NF EN ISO 11821
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UNI EN ISO 11821
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UNE EN ISO 11821
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NEN EN ISO 11821
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DIN EN ISO 3095
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BS EN ISO 3095
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NF EN ISO 3095
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UNI EN ISO 3095
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UNE EN ISO 3095
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NEN EN ISO 3095
1,273
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DIN EN ISO 6508-1
ASTM E8/E 8M
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DIN EN 947
DIN CEN TS 15119-2
NF P 20-501
DIN EN 1026
BS EN 14351-1:2006+A2:2016
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CSTB - Grenoble
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DIN EN 1279-2
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CTK-Poliklinik
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DC VOLTAGE
DC Resistance
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AC Current Generation
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Campbell Associates
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Sound Calibrators
FREQUENCY
Microphones
based:
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BS ISO 488:2008, 2446:2008 and
on BS 4401:Part 3:1970(1986)
BS 696-2:1989 (superseded and
BS ISO 6731:2010
ISO BS EN 3727-1:2002
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Electrolytes in blood serum:
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(Chlamydia pneumoniae, Mycoplasma
urine:
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Carl Zeiss
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DIN EN 60601-1
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IEC 80601-2-77
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Carl Zeiss IQS Deutschland
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Carl Zeiss Industrielle ≤ 3818 mm
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1) In den CMC sind die erweiterten Messu
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DIN EN 61010-1
VDE 0411-1
IEC 61010-1 : 2010
DIN EN 60825-1
VDE 0837
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Parallelendmaße * 0,5 mm
DIN EN ISO 3650:1999
Parallelendmaße * 40 mm
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(cdt), Deletion an Pos 117
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angeborener Chromosomensatz
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Cenata
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Calibration of pressure
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common mode pressure of 3.5
Hydraulic pressure (gauge)
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Whole genome sequencing (WGS:
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CheckImmune
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Leukozytenzahl
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HLA-DR
Leukozytensubpopulationen
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(HSG 248) – 2021
SRV-002 based on HSG 248
(PCM) based on HSG 248
CoMech Metrology
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Chronic progressive external
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Internal
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Coesfeld
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Kraft (WPM)
Belastungseinrichtungen von
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