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
🇪🇸
UNE EN ISO 3095
🇳🇱
NEN EN ISO 3095
1,516
Accredited labs
17
Countries
Showing 251–275 of 345 labs
ISO 6579-1
ISO 15213-2
ISO 11290-1
ISO 7932
F100 based on BS EN ISO
+ 3 more
Pullman Instruments (UK)
Active
DC CURRENT
Measurement
DC VOLTAGE
AC Current Generation
DC RESISTANCE (cont’d)
+ 3 more
Quality Consultants (NI)
Active
(HSG 248) – 2021
(PCM) based on HSG 248
QSOP 03 based on HSG 248
R-TECH Services
Active
ÖNORM EN ISO 17637
BS EN ISO 15614-1:2017
ASTM A 370
DIN EN 10080
BS EN ISO 9015-1:2011
+ 3 more
Ramcare
Active
DC CURRENT
DC VOLTAGE
thermometer Pt100
ROTATIONAL SPEED
Generate
+ 3 more
Rhopoint Metrology
Active
(Steel and tungsten carbide)
LENGTH (cont’d)
pneumatic tyres (See Note 1)
LENGTH (cont.)
Plain plug gauges (taper)
+ 3 more
Richard L Thomas Associates
Active
(HSG 264, 2012)
HSG 264 (2012) and Appx. 3 of
HSG 227 (2004))
Appendix 5 of HSG 227 (2004))
(HSG 248) – 2021
OP11 based on HSG 248
(PCM) based on HSG 248
OP04 based on HSG 248
SARIA
Active
AM-01 based on BS 4401:Part 1:
AM-32 based on BS 4401:Part 4:
AM-03 based on BS ISO 937:2023
AM-04 based on BS ISO
AM-31 based on BS EN ISO
+ 3 more
SATRA Technology Centre
Active
ISO 4931:1986 (withdrawn)
ISO 3759:1984 (withdrawn)
DIN EN 13759
DIN EN 12150-1
DIN EN ISO 15797
+ 3 more
SGS United Kingdom
Active
Joint IP/ASTM methods marked
IP 195*ASTM D1078
ASTM D847 by titration
ASTM D848
ASTM D 1353
+ 3 more
SGS United Kingdom
Active
(HSG 248) – 2021
ASB/SOP/OM8 based on HSG 248
(PCM) based on HSG 248
SGS United Kingdom
Active
CHEM014 based on BS 4401
based on BS 4401 Part 4:1970
CHEM018 based on BS 4401
CHEM023 based on BS 4401-
ISO 6579-1
+ 3 more
SGS United Kingdom
Active
Method CBG-M-SOP-027 based on BS EN ISO
AM01 based on BS EN ISO 4833-1:
2) Method CBG-M-SOP-038 based on BS ISO
ISO 10272-2
Method CBG-M-SOP-007 based on BS EN ISO
+ 3 more
SGS United Kingdom
Active
MPV Thrombozytenvolume
Gas meters
Power meter method
LENGTH
Waterdraw Method
+ 3 more
SGS United Kingdom
Active
BS EN 286 - Simple unfired pressure
BS EN 13445 Unfired pressure
BS EN13480 Metallic industrial
BS EN 12953 Shell boilers
BS EN BS EN 12952 Water-tube
+ 3 more
SOCOTEC Asbestos
Active
(HSG 248) – 2021
SCI/ASB/003 based on HSG 248
(PCM) based on HSG 248
SCI/ASB/001 based on HSG 248
Safe Gas Cylinders
Active
BS EN 1440:2016 + A1:2018 +
EN ISO 23088:2020
Cylinders EN ISO 10460:2018
EN 14208:2004
Safety Advice Centre
Active
M002based on HSG 248
(HSG 248) – 2021
(PCM) based on HSG 248
No matching labs found.