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 1,226–1,250 of 1,516 labs
Tetra Tech Consulting
Active
(HSG 248) – 2021
RPSCA1 based on HSG 248
(PCM) based on HSG 248
RPSCA2 based on HSG 248
BS 7592:2008, BS 8554:2015
+ 2 more
TetraTec Instruments
Active
Railway brakes — disc brake pads (UIC 54
Volumendurchfluss bzw.
0,01 m
Railway pantographs — requirements for m
39 mL/h
+ 3 more
The Auditing Company
Active
#EN ISO 5164:14
# EN 116-97
# ISO 13736
NEN 4400-1
#ISO 6618
DC CURRENT
DC Resistance
Measurement
DC VOLTAGE
CAPACITANCE
+ 3 more
(HSG 248) – 2021
03 based on HSG 248)
QOP01 based on HSG 248
(PCM) based on HSG 248
The Original Gauge Company
Active
LENGTH
Screw ring gauges (parallel)
LENGTH cont.
As for Involute Spline Gauges
See Note 2
+ 3 more
The Testing Lab
Active
DIN EN 933-11
BS EN ISO 17892-1:2014+A1:2022
BS EN ISO 17892-10:2018
BS EN ISO 17892-11:2019
BS EN ISO 17892-2:2014
+ 3 more
Thermo Electron LED
Active
- Gleichspannung
Messgeräte 0,001 V bis
0,33 V bis
3,3 V bis
330 V bis
+ 3 more
Thomas Dudley
Active
BS 1212-2:1990 Clause 4
BS 1212-3:1990 Clause 4
DIN EN 997
Laktoseintoleranz (LCT -14055
BS 1212-4:1991 Clause 4, 13, 14
Masse oder
Konventioneller
Wägewert/
Massenormal *)
> 1 mg
+ 3 more
Railway brake — magnetic track brakes (U
Kraft (WPM)
Länge (WPM)
a) nur Vor-Ort-Kalibrierungen
Vickers hardness test (ISO 6507)
+ 3 more
Total Clean Air
Active
ISO 14644-3
BS EN ISO 14644-2:2015:Part 2
DIN EN 12469
BS EN ISO 14644-1:2015
BS EN ISO 14644-4:2022
+ 3 more
Trescal
Active
- Gleichspannung
/ Messgeräte
10 V; 100 V; 1000 V
> 100 mV
> 0,22 V
+ 3 more
Tru-Cal Metrology
Active
including dial and digital
LENGTH (cont’d)
Plain plug gauges (taper)
ANCILLARY MEASUREMENTS
Plain ring gauges (taper)
+ 3 more
Tyneside Standards
Active
Micrometers
See Notes 3 and 5
See Note 6
Caliper
length bars) – See Note 5
+ 3 more
UNE-EN 60903
UNE-EN IEC 61243-1
UNE-EN 50508
UNE 204001
UNE-EN 61111
+ 2 more
TÜV NORD CERT
Active
IEC 61000-4-39
IEC 61000-4-3: 2006
VDE 0847-4-3
IEC 61000-4-4: 2012
VDE 0847-4-4
+ 3 more
No matching labs found.