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
🇳🇱
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
Accredited labs
17
Countries
Showing 276–300 of 345 labs
Scientific Services
Active
(HSG 248) – 2021
D3TA2 based on HSG 248
(PCM) based on HSG 248
D3TA8 based on HSG 248
Scopus Asbestos Compliance
Active
(HSG 248) – 2021
SAC-SOP-15 based on HSG 248
SAC-SOP-07 based on HSG 248
staining based on HSG 248
SembCorp Utilities (UK)
Active
(HSG 248) – 2021
DI/AN/ME/025 based on HSG 248
DI/AN/ME/001 based on HSG 248
DI/AN/ME/026 based on HSG 248
(PCM) based on HSG 248
ServiceCal
Active
PRESSURE (cont’d)
DC CURRENT
DC VOLTAGE
CFH-Gen, Macula-Degeneration
Measurement
+ 3 more
LENGTH
Plain plug gauges (parallel)
Internal
Caliper
LENGTH (cont’d)
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Shirley Technologies
Active
ASTM E 2149-20
BS EN ISO 20743:2021 Section
ISO 14119
BS EN ISO 20645:2004
BS 1425-1:1991 Appendix A
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Sigma-HSE (UK)
Active
DIN EN 13821
Sigma-HSE (UK) Ltd
DIN EN 14034-1
BS EN ISO/IEC 80079-20-2:2016
DIN EN 14034-2
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Somerset Council
Active
(HSG 248) – 2021
R24 based on HSG 248
staining based on HSG 248
ELECTRICAL CALIBRATION
DC RESISTANCE (continued)
DC Resistance
AC VOLTAGE (continued)
AC CURRENT
+ 3 more
based on BS EN ISO 6579-1:
ISO 21528-2
ISO 21149:2017+Amd1:2022
DIN EN ISO 18415
method based on BS ISO 16649-2:
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Speciality Steel UK
Active
ISO 3651-2
ASTM E 384-22
ASTM E10-23
ISO 6506-1
ASTM A262-15(2021) Practice E
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Spectra Analysis Services
Active
QOP01 based on HSG 248
(HSG 248) – 2021
(PCM) based on HSG 248
(HSG 264, 2012)
Appendix 5 of HSG 227 (2004))
AM01 based on BS EN ISO 4833-1:
AM03 based on BS EN ISO 11290-
AM05 based on BS ISO 21528-2:
AM08 based on BS EN ISO 15213-2:2023 by
AM12 based on BS EN
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Springfields Fuels
Active
LMM2149, ASTM E112-13 by
ISO 6507-1
LMM2207, ASTM E112-13 by
LMM1862, ASTM E112-13 for
to BS EN ISO 6507-1:2018
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Starna Scientific
Active
Sealed liquid cells containing
prepared from NIST SRM 935a
Toluene/Hexane
Neutral density glass filters
Neutral density glass filter
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Surrey County Council
Active
DIN EN 933-11
DIN EN 1097-6
DIN EN 1097-1
DIN EN 1097-2
DIN EN 933-3
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T-SQUARED Validair
Active
ISO 14644-3
DIN EN 12469
BS 7989:2001
BS EN ISO 14644-1:2015
DIN EN 14175-3
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