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
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UNE EN ISO 3095
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NEN EN ISO 3095
1,273
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Navobi
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AM09 based on BS ISO 21527-1:
07L.1.11 based on ISO 5984:2002
DIN EN ISO 11290-2
ISO 4833-1
DIN EN ISO 8968-1
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Nemko S.p.A. a socio unico
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DIN EN 62368-1: 2016
DIN EN 61326-2-6
DIN EN 61010-2-101
EN IEC 62368-1
IEC 61326-2-6
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DIN EN ISO 7932
DIN EN ISO 6888-1
ISO 15213-1
DIN ISO 16649-2
DIN EN ISO 6888-3
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DIN EN ISO 15061 (D 34)
DIN EN 27888 (C 8)
DIN EN 1484 (H 3)
ISO 5667-21
DIN 38404-C 10
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Normec DETS
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BS 1377: Part 2: 1990
DIN EN 12457
No DETSC 5012 based on BS EN
staining based on HSG 248.
(HSG 248) – 2021
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#EN ISO 5164:14
# EN 116-97
NEN 4400-1
# ISO 13736
#ISO 6618
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Normec Valitech
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Tensile testing of metallic materials (I
positiver Überdruck -0,01 bar
Absolutdruck p
abs
Taupunkttemperatur
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Norsonic-Tippkemper
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Akustik
Übertragungsmaß von
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Messmikrofonen mit
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North Star Environmental
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(HSG 248) – 2021
NSDOC 47 based on HSG 248
staining based on HSG 248.
(PCM) based on HSG 248
Not One Iota
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(HSG 248) – 2021
SOP-12, based on HSG 248
staining based on HSG 248
(PCM) based on HSG 248
Nuclear Restoration Services
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AIR KERMA RATE
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HBs-Antigen (Hepatitis B-Surface
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O.C. Consulting (UK)
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(HSG 264, 2012)
Appendix 5 of HSG 227 (2004)
(HSG 248) – 2021
(PCM) based on HSG 248
UNE-EN 14385
UNE-EN 15259
UNE-EN 13211
BS ISO 9096:2017
UNE 77216
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ONNEKEN Meß- und Prüftechnik
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Druck 0,03 bar
Absolutdruck Pabs
> -0,3 bar
> 3,0 bar
> −0,02 bar
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OPTOLUTION Messtechnik
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− Wärmezähler
Durchflusssensoren
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IEC 61400-23
ASTM G73 (2012)
IEC 60885-3, 2.4.1
IEC 60502-2
IEC 60840
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ISO 11819-1
(N 2 O) 0,000008
DIN EN ISO 16911-1
AG2 and IS EN 15259:2007
DIN EN 14790
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One Scientific
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ISO 6888-1
ISO 21528-2
BS ISO 4832:2006
ISO 4833-1
ISO 6579-1
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Optical Test & Calibration
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DC Resistance
DC CURRENT
DC VOLTAGE
DC RESISTANCE (cont’d)
DIN EN 1264-5
DIN EN 13647
DIN EN 71-10
DIN EN 50642
DIN EN ISO 14184-2
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