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
🇮🇹
UNI EN ISO 11821
🇪🇸
UNE EN ISO 11821
🇳🇱
NEN EN ISO 11821
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DIN EN ISO 3095
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BS EN ISO 3095
🇫🇷
NF EN ISO 3095
🇮🇹
UNI EN ISO 3095
🇪🇸
UNE EN ISO 3095
🇳🇱
NEN EN ISO 3095
1,516
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Basophile Granulozyten
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Laborgemeinschaft Köln
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Ristocetin Kofactor Aktivität
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PRESSURE (cont’d)
Distortion Factor
Spot frequency
Phase angle
(Herpes simplex virus type
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(HSG 248) – 2021
(PCM) based on HSG 248
P-12 based on HSG 248
(HSG 248) – 2021
(PCM) based on HSG 248
ISO 12966-2
F06 6 & F06 5 based on BS EN
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DIN EN 16174
DIN CEN ISO/TS 16179
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Leadec BV &
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Gleichspannung 33 mV
Messgeräte 0,33 V
330 V
Gleichstromstärke 33 µA
Messgeräte 0,33 mA
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Leftfield Environmental
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(HSG 248) – 2021
LSOP6 based on HSG 248
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(ein- und mehrgängige
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Außengewinde
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DIN EN 60601-2-4
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anteile
Kohlenstoffmonoxid
Kohlenstoffdioxid
Methan
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accordance with (EN ISO 14644-
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London Borough of Enfield
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staining based on HSG 248
(HSG 248) – 2021
(PCM) based on HSG 248
London Laboratories
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(HSG 248) – 2021
ASB04 based on HSG 248
(PCM) based on HSG 248
Lucideon
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DIN EN 772-13
DIN EN 1052-2
DIN EN 772-20
DIN EN 772-14
DIN EN 1052-4
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