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
1,516
Accredited labs
17
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Showing 101โ125 of 345 labs
Gas pressure (absolute)
Gas pressure (gauge)
Hydraulic pressure (gauge)
Hydraulic Pressure (absolute)
PRESSURE (contโd)
+ 1 more
DM Calibration
Active
LENGTH
Blade type
Straight edges
Surface plates
External micrometer
+ 3 more
DNKA
Active
staining based on HSG 248.
(PCM) based on HSG 248
(HSG 248) โ 2021
QSOP 03 based on HSG 248
QSOP 01 based on HSG 248
Decus Research
Active
1) MS08P based on BS EN ISO
MS02P based on BS EN ISO
MS03P based on BS EN ISO
MS06P based on BS EN ISO
MF07P based on BS EN ISO
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Devonport Royal Dockyard
Active
Specific Values 1 ๏
RF Power
RF Attenuation 10 MHz to 1 GHz
Other values -20 dBm to +20 dBm
Devonport Royal Dockyard
Active
BS 4206:1967 (superseded)
ISO 5173
ISO 7438
BS EN ISO 9606-2:2004
BS 131-5:1965
+ 3 more
and Appx. 3 of HSG 227 (2004))
in Appendix 5 of HSG 227 (2004)
guides HSG 264 (2012) and
(HSG 264, 2012)
ERC Testing
Active
DIN EN 1863-1
BS EN ISO 10077-1:2006
published 2024) for BS EN
DIN EN 1863-2
BS EN ISO 10077-2:2017
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Efectis UK/Ireland
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EN 1364-3
DIN EN 1366-4
EN 1364-4
BS 476-21
BS 476-22
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(HSG 248) โ 2021
(PCM) based on HSG 248
based on BS EN 12457
DIN EN 1948-4
dbSNP rs1800562, rs1799945, rs1800730, r
(HSG 264, 2012)
HSG 227 (2004))
(HSG 248) โ 2021
(PCM) based on HSG 248
ISO 3651-2
ASTM A262 Methods A, C & E
ISO 7438
ASTM G28-2022 Method A
ASTM G48 Method A
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DIN EN 1303
DIN EN 12209
DIN EN 14846
BS 3621:2007+A2:2012
BS 8621:2007+A2:2012
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Enertek International
Active
DIN EN 12279
DIN EN 12278
-22018G/A, rs182549
DIN EN 303-2
DIN EN 15502-2-1
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Enquin Environmental
Active
(HSG 248) โ 2021
(Section 2) based on HSG 248
(Section 4) based on HSG 248
staining based on HSG 248
(HSG 264, 2012)
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Enviraz Surveys
Active
HSG 264 (2012) and Appx. 3 of
(HSG 264, 2012)
HSG 227 (2004))
Appendix 5 of HSG 227 (2004))
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