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
🇫🇷
NF EN ISO 3095
🇮🇹
UNI EN ISO 3095
🇪🇸
UNE EN ISO 3095
🇳🇱
NEN EN ISO 3095
1,273
Accredited labs
15
Countries
Showing 951–975 of 1,273 labs
Schütz + Licht Prüftechnik
Active
Kraft (WPM)
Werkstoffprüfmaschinen
Acoustics — tonality assessment (DIN 456
Länge (WPM)
messeinrichtungen von
+ 3 more
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
ETSI EN 319 412
ETSI EN 319 401
ETSI EN 319 411-2
ETSI EN 319 411-1
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)
+ 3 more
DIN EN ISO 12185
ASTM D 4052
DIN EN ISO 3405
DIN EN 13016-1
DIN EN 13016-2
+ 3 more
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
+ 3 more
ISO 37
ISO 8513
DIN EN 1393
ISO 21527-2
DIN EN ISO 527-4
+ 3 more
Thermodynamische Messgrößen
Temperaturmessgrößen
- Direktanzeigende Thermometer
Railway brake handbooks (UIC 547)
- Thermopaare, Thermoelemente
+ 3 more
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
+ 3 more
Somerset Council
Active
(HSG 248) – 2021
R24 based on HSG 248
staining based on HSG 248
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:
+ 3 more
Verschlußzeit Kollagen/ADP
Kollagen/Epinephrin
Basophile Granulozyten
Eosinophile Granulozyten
Erythrozyten
+ 3 more
Verschlußzeit Kollagen/ADP
Kollagen/Epinephrin
Basophile Granulozyten
Eosinophile Granulozyten
Erythrozyten
+ 3 more
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
+ 3 more
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
+ 3 more
FM003 based on ISO 6888-
FM004 based on ISO 16649-2:2001
FM006 based on ISO 6579-1:2017+Amd 1:202
FM009 based on ISO 11290-1:2017
2) WM005 based on ISO 9308-2:2012 using
+ 1 more
Kraft
Vibration measuring instruments — requir
Sound power — survey method (ISO 3746)
1 kN
Railway brake — automatic variable load
+ 3 more
Großes Blutbild
Kleines Blutbild
Erythrozyten
Hämoglobin
Hämatokrit
+ 3 more
Lehrdorne
Durchmesser 1 mm
Lehrringe
Prüfstifte
Messschieber für 0 mm
+ 3 more
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