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
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NEN EN ISO 3095
1,516
Accredited labs
17
Countries
Showing 1,176–1,200 of 1,516 labs
Großes Blutbild
Kleines Blutbild
Erythrozyten
Hämoglobin
Hämatokrit
+ 3 more
Starna Scientific
Active
Sealed liquid cells containing
prepared from NIST SRM 935a
Toluene/Hexane
Neutral density glass filters
Neutral density glass filter
+ 3 more
Lehrdorne
Durchmesser 1 mm
Lehrringe
Prüfstifte
Messschieber für 0 mm
+ 3 more
Parallelendmaße aus 0,5 mm
Parallelendmaße aus
Keramik nach 0,5 mm
Wolframkarbid nach 0,5 mm
DIN EN ISO 3650:1999
+ 3 more
Studenroth Präzisionstechnik
Active
− Parallelendmaße
− Durchmesser
− Längenmessmittel
Railway brake — magnetic track brakes (U
− Längenmessgeräte
+ 3 more
WBC (Leukozyten)
RBC (Erythrocyten)
HGB (Hb)
HCT (Hk)
PLT (Thrombozyten)
+ 3 more
Suchy Messtechnik
Active
Druck 50 mbar
Absolutdruck Pabs
> 1,3 bar
> 2,5 bar
> 0,6 bar
+ 3 more
Surrey County Council
Active
DIN EN 933-11
DIN EN 1097-6
DIN EN 1097-1
DIN EN 1097-2
DIN EN 933-3
+ 3 more
SysKal
Active
Hexagon Metrology Raumdiagonale von
GmbH, Wetzlar, D ≤ 1500 mm
Polyworks, Software von
InnovMetric, Lindau, D
PowerINSPECT, Software
+ 3 more
ISO 5-3
ISO 12647-1
ISO 13655
ISO 3074
DIN EN ISO 1833-4
DIN EN ISO 1833-5
DIN EN ISO 1833-6
DIN EN ISO 1833-7
+ 3 more
T-SQUARED Validair
Active
ISO 14644-3
DIN EN 12469
BS 7989:2001
BS EN ISO 14644-1:2015
DIN EN 14175-3
+ 1 more
DIN ISO 11466
UNE-EN 12880
ÖNORM EN 12457-4
ISO 10523
DIN EN 27888
+ 3 more
TAK CERT
Active
− Scheinwerfer-Einstell-Prüfsystem
− Abgasmessgeräte für Fremdzündungsmotor
− Abgasmessgeräte für Kompressionszündun
Railway brake — magnetic track brakes (U
nur Vor-Ort-Kalibrierungen
+ 3 more
TARKETT France
Active
DIN EN ISO 717-2
DIN EN ISO 10140-3
DIN EN 1081
DIN EN ISO 105-B02
DIN EN ISO 9239-1
+ 3 more
TECNATOM, S.A. (Unipersonal)
Active
UNE 73109
IEC 60780 (1998)
UNE 73109 (2001)
ISO 28218
ISO 27048
UNE-EN ISO 14644-3
UNE-EN ISO 14644-1 (sin realizar toma se
ISO 14644-3
UNE-EN 12469
- Gleichspannung
/ Messgeräte
0,1 mV
> 220 mV
> 2,2 V
+ 3 more
TERANA PUY-DE-DOME
Active
NF T 90-412
NF U47-101
DIN EN ISO 7899-1
DIN ISO 16649-2
DIN EN ISO 6888-2
+ 3 more
TES Time Elektronik Struck
Active
Elektrische Messgrößen
Gleichstrom- und Niederfrequenzmessgröße
Railway brake — magnetic track brakes (U
− Gleichspannung
− Gleichstromstärke
+ 3 more
No matching labs found.