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
🇩🇪
DIN EN ISO 11821
🇬🇧
BS EN ISO 11821
🇫🇷
NF EN ISO 11821
🇮🇹
UNI EN ISO 11821
🇪🇸
UNE EN ISO 11821
🇳🇱
NEN EN ISO 11821
🇩🇪
DIN EN ISO 3095
🇬🇧
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 351–375 of 1,516 labs
DIN EN ISO 11357-4
IEC 61037
DIN EN ISO 13850
DIN EN ISO 13855
ISO 14119
+ 3 more
DIN 58620: 2007-02
DIN 58621: 2011-10
DIN 58647-7: 1997-12
ID136
> 140
+ 3 more
IEC 61400-12
IEC 61400-12-1
IEC 61400-12-2
IEC 61400-12-3
IEC 61400-12-5
+ 3 more
Railway brakes — conditions for homologa
− Durchfluss von Flüssigkeiten
− Strömungsgeschwindigkeit von Gasen
− Widerstandsthermometer
− Temperatur-Transmitter, Datenlogger
+ 3 more
ADP
ASPI
TRAP
Amiodaron, Desethylamiodaron
Mycophenolsäure
+ 3 more
Devonport Royal Dockyard
Active
Specific Values 1
RF Power
RF Attenuation 10 MHz to 1 GHz
Other values -20 dBm to +20 dBm
Devonport Royal Dockyard
Active
BS 4206:1967 (superseded)
ISO 5173
ISO 7438
BS EN ISO 9606-2:2004
BS 131-5:1965
+ 3 more
Diagenom
Active
Chromosomensatz (angeboren)
Chromosomensatz (erworben)
Adrenogenitales Syndrom
Angelman-Syndrom (15q11-Region, UBE3A)
Mikrodeletionen; AZFa-c)
+ 3 more
Diagnos MVZ
Active
HbA1c
Differentialblutbild, maschinell
Retikulozyten, maschinell
Kleines Blutbild
Thrombozyten
+ 3 more
Diehl Metering
Active
Volumen strömender 0,0005 m
− Durchfluss von Flüssigkeiten
0,025 m
Wasserzähler und 0,001 m
Durchflusssensoren
+ 3 more
DIN EN ISO 7730
EPA 6020
DIN EN ISO 6888-1
ISO 14698-1
ISO 4832
+ 3 more
Absolutdruck p *
Vickers hardness test (ISO 6507)
Flüssigkeitsvolumen *
variablem Volumen
aufnehmern sowie
+ 3 more
Staber & Kollegen
Active
Blutbild groß
Thrombozyten
Urinsediment
Natrium
Kalium
+ 3 more
Aminosäureprofil
Guanidinoacetat
Kreatin
Hämoglobinprofil
Nitisinon (NTBC), Succinylaceton
+ 3 more
Druck *
Negativer und
positiver Überdruck -0,01 bar
Positiver Überdruck p e
> 0,015 bar
+ 3 more
Duravit
Active
*6095991, BAG3 [OMIM *6038831
(-13910T>C) rs4988235
- PiM rs6647, PiZ rs28929474, rs17580
DIN EN 997
DIN EN 13407
+ 3 more
VDE 0468-2-1
VDE 0468-2-2
VDE 0468-2-6
DIN EN IEC 60068-2-11
DIN EN IEC 60068-2-13
+ 3 more
optische 0 mm
Werkzeugeinstell- und
/ Messgeräte
verwendete Abkürzungen:
ECOSISTEM
Active
DIN EN ISO 9308-2
EPA 5035
DIN EN 14789
EPA 5030
DIN EN 14790
+ 3 more
DIN 40633-2
DIN 40633-3
DIN 53482
DIN 72551-100
DIN 72551-6
+ 3 more
and Appx. 3 of HSG 227 (2004))
in Appendix 5 of HSG 227 (2004)
guides HSG 264 (2012) and
(HSG 264, 2012)
EGIS INDUSTRIE ET PROCESS
Active
DIN EN 12469
NF S 90-351
BS EN ISO 14644-1:2015
ISO 14644-3
EICHROM AMIANTE
Active
NF X 43-269 - Annexe K
NF X 43-050 (parties utiles
NF X 46-032
NF X 43-269 – Annexe K
NF X 43-050
+ 1 more
No matching labs found.