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 76–100 of 345 labs
Based on ISO 10312:2019 and ISO
SOP 16 by XRD (ISO BS EN
C G C Laboratory
Active
(HSG 248) – 2021
(PCM) based on HSG 248
SOP 5, based on HSG 248
SOP 4, based on HSG 248
C.W.E. Services
Active
(HSG 264, 2012)
HSG 227 (2004))
Safety Executive guides HSG 264
(2012) and App 3 of HSG 227
(HSG 248) – 2021
+ 3 more
DIN EN 13284-1
BS ISO 9096:2017
requirements of BS EN 15259:2007
Standard and BS EN 15259:2007
DIN EN ISO 16911-1
+ 3 more
DC VOLTAGE
DC Resistance
DC CURRENT
AC Current Generation
Generation (continued)
+ 3 more
Campbell Associates
Active
Sound Calibrators
FREQUENCY
Microphones
based:
½” & ¼” microphones @ 250 Hz
+ 3 more
BS ISO 488:2008, 2446:2008 and
on BS 4401:Part 3:1970(1986)
BS 696-2:1989 (superseded and
BS ISO 6731:2010
ISO BS EN 3727-1:2002
+ 3 more
Electrolytes in blood serum:
Enzymes in blood serum:
(Chlamydia pneumoniae, Mycoplasma
urine:
Hormones in blood serum:
+ 1 more
Cavendish Laboratories
Active
(cdt), Deletion an Pos 117
(HSG 248) – 2021
(PCM) based on HSG 248
BS 6068-4.12:1998 (withdrawn)
Chamois Metrology
Active
Calibration of pressure
Gas pressure (gauge)
Gas Pressure (Differential)
common mode pressure of 3.5
Hydraulic pressure (gauge)
+ 3 more
Liquid-in-glass thermometers
ASTM D4052 (Digital density
Cirrus Research
Active
Sound Calibrators
Sound Level Meters
One-third octave band filters
(HSG 248) – 2021
SRV-002 based on HSG 248
(PCM) based on HSG 248
CoMech Metrology
Active
Chronic progressive external
Depth
Internal
Dial gauges and dial test
Caliper
+ 3 more
simulation.
parameters and ranges)
digital and analogue
Compli Group
Active
DC CURRENT
DC Resistance
Oscilloscope Calibration
DC VOLTAGE
CAPACITANCE
+ 3 more
DIN EN 933-11
DIN EN 12390-3
DIN EN 933-3
DIN EN 12390-7
DIN EN 12697-5
+ 3 more
DC CURRENT
LENGTH
DC Resistance
DC VOLTAGE
Cold junction compensation
+ 3 more
Corserv Solutions
Active
DIN EN 933-1
(PCM) based on HSG 248
(HSG 248) – 2021
DIN EN 932-1
DIN EN 932-2
+ 3 more
No matching labs found.