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
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NEN EN ISO 3095
1,516
Accredited labs
17
Countries
Showing 126–150 of 1,516 labs
Asbestos Analytical Services
Active
(HSG 248) – 2021
LSD.ASB.02 based on HSG 248
LSD.ASB.04 based on HSG 248
(PCM) based on HSG 248
(HSG 248) – 2021
QOP03 based on HSG 248
(PCM) based on HSG 248
(PCM) based on HSG 248)
QOP01 based on HSG 248
+ 1 more
Asbestos Solution Providers
Active
(HSG 248) – 2021
(PCM) based on HSG 248
(HSG 264, 2012)
Asbestos Survey & Management
Active
QOP03 based on HSG 248
QOP01 based on HSG 248
(HSG 248) – 2021
(PCM) based on HSG 248
Ashcroft Instruments
Active
Absolutdruck p abs 0,015 bar
> 2 bar
> 42 bar
Absolutdruck Pabs
1 bar; 2 bar
+ 3 more
Aspect Quality
Active
DIN 55635
VDE 0468-2-14
VDE 0468-2-1
VDE 0468-2-5
DIN EN 60068-2-30
+ 3 more
AstraZeneca UK
Active
DC CURRENT
AC VOLTAGE (continued)
AC CURRENT
AC Voltage
DIMENSIONAL
+ 3 more
Analysts’ Guide (HSG 248)
(HSG 248) – 2021 Asbestos: The
(PCM) based on HSG 248
Conformity assessment — requirements for
Druckkraftrichtung
Drehmoment 0,01 N∙m
Drehmomentaufnehmer *
Drehmomentmessgeräte *
+ 3 more
Ayerst Environmental
Active
(HSG 248) – 2021 )
(PCM) based on HSG 248
Surveying) based on HSG 248
IEC 61400-11:2012/ AMD:2018
IEC 61400-12-2
IEC 61400-50-2
IEC 61400-12-1
IEC 61400-12-3
+ 3 more
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