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 1,026–1,050 of 1,516 labs
Pennington Choices
Active
(HSG 264, 2012)
and Appx. 3 of HSG 227 (2004))
Executive guides HSG 264 (2012)
Perry Analytical
Active
(HSG 248) – 2021
(PCM) based on HSG 248
Manual based on HSG 248
Perschmann Calibration
Active
Parallelendmaße * 0,5 mm
DIN EN ISO 3650:1999
> 100 mm
Sonderquerschnitt (rund
Parallelendmaße * > 100 mm
+ 3 more
Temperaturmessgrößen
Widerstandsnormal
thermometer (IPRT)
Zeiss Industrielle
Temperaturmessgrößen −35 °C
+ 3 more
Polytest Ingenieure
Active
DIN EN ISO 9934-1
DIN ISO 815-1
DIN ISO 815-2
DIN ISO 4593
DIN EN 50178: 1998
+ 3 more
Poulten Selfe and Lee
Active
TEMPERATURE
Viscosity constant ‘C’
Reference viscometers:
ASTM D4052 (Digital density
Power Diagnostix Systems
Active
Impulsladung
Anstiegszeit
Impulsdauer
Wechselspannung 1 V
> 1,1 kV
+ 3 more
Differentialblutbild
Erythrozyten
Hämatokrit
Leukozyten
Retikulozyten
+ 3 more
External (Tip) Diameter
Helix (lead) total deviation (F
GEARS SPUR/HELICAL EXTERNAL (cont’d)
As for Involute Spline Gauges
HbA1c
Automatisches Blutbild
Leukozyten
Normoblasten
Retikulozyten
+ 3 more
Calcium
Bilirubin gesamt
Creatinkinase-Muscle-Brain
TPZ nach Quick
Immunglobulin A
+ 3 more
ProfEC Ventus
Active
IEC 61400-12 Ed.1 *
IEC 61400-12-1 Ed.3 *
IEC 61400-12-3 Ed.1 *
IEC 61400-12-4 Ed.1 *
IEC 61400-12-5 Ed.1 *
+ 3 more
Prüf-, Überwachungs- und Zertifizierungsgemeinschaft der Straßenausstatter e.V. - StrAus-Zert
Active
DIN 68877-2
DIN EN ISO 2178
DIN EN 16272-1
DIN EN 12899-1
DIN EN 12899-5
+ 1 more
ISO 15835-2
UNE-EN 10002-1
BS EN ISO 15630-1:2019
UNE-EN 10080
BS EN ISO 15630-3:2019
+ 3 more
ISO 6579-1
ISO 15213-2
ISO 11290-1
ISO 7932
F100 based on BS EN ISO
+ 3 more
Pullman Instruments (UK)
Active
DC CURRENT
Measurement
DC VOLTAGE
AC Current Generation
DC RESISTANCE (cont’d)
+ 3 more
QS-Grimm
Active
Parallelendmaße * 0,5 mm
DIN EN ISO 3650:1999
Zylindrische Normale 1 mm
Innenzylinder *
> 100 mm
+ 3 more
QUALILAB
Active
EN 12966: 2014 Section 4.5.4
DIN EN 55025: 2018
DIN EN 60068-2-30
(CISPR 25:2002) Section 6
ISO 11452-4: 2020
+ 3 more
ISO 13320
VDE 414-9-11
NF V08-250
ISO 19343
DIN EN ISO 7899-1
+ 3 more
Qopas
Active
Koordinatenmessgeräte geräte mit einem
Chorus, Help-PJM von
DEA Hexagon Metrology
S.p.A., Turin, I
Associates EMS Products, ≤ 1500 mm
+ 3 more
Quality Consultants (NI)
Active
(HSG 248) – 2021
(PCM) based on HSG 248
QSOP 03 based on HSG 248
No matching labs found.