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
Accredited labs
17
Countries
Showing 201–225 of 345 labs
Leftfield Environmental
Active
(HSG 248) – 2021
LSOP6 based on HSG 248
(PCM) based on HSG 248
Life Environmental Services
Active
(HSG 248) – 2021
QSOP 01 based on HSG 248
(PCM) based on HSG 248
QSOP 03 based on HSG 248
accordance with (EN ISO 14644-
BS EN ISO 14644-1:2015
London Borough of Enfield
Active
staining based on HSG 248
(HSG 248) – 2021
(PCM) based on HSG 248
London Laboratories
Active
(HSG 248) – 2021
ASB04 based on HSG 248
(PCM) based on HSG 248
Lucideon
Active
DIN EN 772-13
DIN EN 1052-2
DIN EN 772-20
DIN EN 772-14
DIN EN 1052-4
+ 3 more
Lucion Services
Active
staining based on HSG 248
(HSG 248) – 2021
(PCM) based on HSG 248
3492, ISO14966 and HSG 248
DIN EN 14629
+ 3 more
M E Broadstone Limited
Active
Plain ring gauges (taper)
Plain gap gauges (parallel)
Plain plug gauges (taper)
LENGTH
ANGLE
+ 3 more
MP Calibration Services
Active
Plain plug gauges (parallel)
length bars)
LENGTH (continued)
Micrometers
(enzephalomyopathische Form
+ 3 more
MS Laboratories
Active
on BS 4401:Part 3:1970(1986)
ISO 936:1998
BS ISO 21528-2:2017
BS ISO 16649-2:2001
ISO 6888-1
+ 3 more
MSS Consulting
Active
(HSG 264, 2012)
Appendix 5 of HSG 227 (2004)
Appendix 3 of HSG 227 (2004)
(HSG 248) – 2021
(PCM) based on HSG 248
+ 1 more
Marfleet Microbiology
Active
ISO 6579-1
ISO 21528-2
ISO 16649-2
TP/007 based on BS ISO
ISO 11290-2
+ 3 more
Meridian Technical Services
Active
BS EN 14876:2007/Internal proceduresDiss
BS EN ISO 18119:2018+A1:2021
BS EN ISO 22434:2011
BS EN ISO 10460:2018
BS EN ISO 13769:2018
tungsten carbide)
Plain ring gauges (taper)
Straight edges
LENGTH (cont’d)
Squares
+ 3 more
Micro Precision (Midlands)
Active
LENGTH
Caliper
Depth BS 6468: 2008, 0 to 300
Depth
Dial gauges and dial
+ 2 more
Microtech Services (Wessex)
Active
ISO 7251
# = 100 A
ISO 6888-3
1) A:2b based on ISO 4833-2:2013 Amd 1:2
2) A:6c based on ISO 21528-1:2017 by mos
+ 1 more
Moorcroft Controls
Active
DC CURRENT
Gas pressure (gauge)
ELECTRICAL
DC VOLTAGE
Measurement
+ 3 more
NSF Wales Limited
Active
BS EN ISO 7686:2005
DIN EN 997
DIN EN 13079
DIN ISO 10381-7
DIN EN 14622
+ 3 more
No matching labs found.