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
1,273 Accredited labs
15 Countries

Showing 526–550 of 714 labs

DAkkS D-PL-19381-01-02 Neu-Isenburg, DE
IEC 61851-1: 2010 IEC 61851-23 IEC 62109-1 IEC 62109-2 IEC 61010 + 3 more
View Profile
DAkkS D-K-19403-01-00 Grävenwiesbach, DE
Messschieber für 0 mm Außen-, Innen- und Bügelmessschrauben 0 mm Messuhren mit Feinzeiger + 3 more
View Profile
DAkkS D-ML-13082-01-00 Regensburg, DE
Achromatopsie (Panel) (ATF6, CNGA3, CNGB Albinismus (OCA2) Alport-Syndrom (Panel) (COL4A1, COL4A3, Amyloidose (Panel) (APOA1, APOA2, APP, B Arrhythmien (Panel) (ACTC1, ACTN2, BAG3, + 3 more
View Profile
DAkkS D-PL-11027-01-01 Stuttgart, DE
DIN EN 442-2 DIN EN 16430-1 DIN EN 16430-2 DIN EN 16430-3 DIN 4703-3 + 3 more
View Profile
DAkkS D-K-11027-01-02 Stuttgart, DE
Sound power — engineering method using a Sound power — survey method (ISO 3746) Sound power — in-situ using reference so Sound intensity — scanning method (ISO 9 Sound intensity — scanning method part 2 + 3 more
View Profile
DAkkS D-ML-13154-02-00 Aachen, DE
Syndrom/Silver-Russell-Syndrom) SMN1 (SMA) FMR1-Gen (fraX, POF, FXTAS) Charcot-Marie-Tooth-Erkrankung Cardiolipin (CMT) + 3 more
View Profile
DAkkS D-ML-13154-03-00 Aachen, DE
Adrenalin Dopamin 5-Hydroxyindolessigsäure Homovanillinsäure Noradrenalin + 3 more
View Profile
DAkkS D-ML-13154-02-01 Aachen, DE
(Long Read): SNV, CNV, Repeats FMR1-Gen (fraX, POF, FXTAS) Charcot-Marie-Tooth-Erkrankung Cardiolipin (CMT) GARS1, GDAP1, GJB1, HSPB1, IGHMBP2, LITA + 3 more
View Profile
DAkkS D-ML-13154-01-01 Aachen, DE
Leukozyten (WBC) Erythrozyten (RBC) Hämatokrit (HCT) MCV Thrombozyten + 3 more
View Profile
DAkkS D-ML-13125-01-00 Bonn, DE
Thrombozytenaggregation Agonisten: ADP, ADP-PGE1, heparininduzierter Antikörper Heparin induzierter Thrombozytopenie Typ II (HIT II) + 3 more
View Profile
DAkkS D-ML-13125-03-01 Bonn, DE
Bannayan-Ruvalcaba-Riley-Syndrom (institutseigene Erweiterung des Illumina TruSight Cancer Panel): PTEN, AKT1, PIK3CA, SEC23B Syndrom (institutseigene + 3 more
View Profile
DAkkS D-ML-13125-02-00 Bonn, DE
Amiodaron, Desethylamiodaron HbA1c Vitamin A, Vitamin E Vitamin B1/B6 Vitamin B2 + 3 more
View Profile
DAkkS D-ML-19730-02-00 Dresden, DE
angeborener Chromosomensatz Nummerische Veränderungen Chromosomen 13, 18, 21, X und ldentifizierung kleinster chromosomaler/numerischer + 3 more
View Profile
DAkkS D-ML-19730-01-00 Dresden, DE
Multiplate-Analyse (TRAP, ADP) Thrombozytenaggregation Born) Organische Säuren (Profil) Metanephrin, Normetanephrin + 3 more
View Profile
DAkkS D-ML-19730-06-00 Dresden, DE
Blutbild, Differentialblutbild Differentialblutbild Fragmentozyten Knochenmarkzytologie Liquor- und Ergusszytologie + 3 more
View Profile
DAkkS D-ML-13362-05-00 Düsseldorf, DE
Familiärer Brust- und Eierstockkrebs (TruRiskGenePanel des Deutschen Konsortiums Familiärer Brust- und Eierstockkrebs) (ATM, BARD1, BRCA1, BRCA2, BRIP1, CDH1, + 1 more
View Profile
DAkkS D-ML-13362-04-00 Düsseldorf, DE
Cyclosporin Everolimus Sirolimus Cyclosporin A, Everolimus, Sirolimus, Ta Vitamin A + 3 more
View Profile
DAkkS D-ML-13362-01-01 Düsseldorf, DE
Pilze (Dermatophyten, Schimmelpilze, Spr Mykobakterien anaerobe Bakterien, anspruchsvolle Schnellwachsende aerobe Cefinase-positive Bakterien + 3 more
View Profile
DAkkS D-ML-13297-07-01 Erlangen, DE
Azoospermie (AZFa,b, c Deletionen) Huntington (HTT) Fra(X)-Syndrom, FXTAS (FMR1) Familiärer Brust- und Eierstockkrebs (ATM (NM_000051), BRCA1 + 3 more
View Profile
DAkkS D-ML-13297-06-00 Erlangen, DE
Thrombozytenaggregation ASPI, COL, RISTO, TRAP) Steroide Profil 11-Deoxycortisol 11-Deoxycorticosteron + 3 more
View Profile
DAkkS D-ML-13297-08-00 Erlangen, DE
Interleukin 23 Rezeptor HLA-B27 HLA-A-Locus HLA-B-Locus HLA-C-Locus + 3 more
View Profile
DAkkS D-ML-13297-02-00 Erlangen, DE
Amitriptylin Bromazepam Chlordiazepoxid Clobazam Clomipramin + 3 more
View Profile
DAkkS D-ML-13297-03-00 Erlangen, DE
Aspergillus fumigatus AK Brucella spp.- Ak Candida spp. - Ak Cardiolipin AK Cryptococcus neoformans + 3 more
View Profile
DAkkS D-ML-13297-01-00 Erlangen, DE
maschinelles Blutbild maschinelles Differentialblutbild DRVVT, Lupus Antikoagulantien Protein S (Aktivität) Exogene Gerinnungsfaktoren + 3 more
View Profile
DAkkS D-ML-13297-04-00 Erlangen, DE
Mycoplasma pneumoniae-DNA Bordetella pertussis- DNA Legionella pneumophila-DNA HIV-1, 2, Ak, Bestätigungstest Adenovirus IgA-Ak + 3 more
View Profile

No matching labs found.

Industries

Railway rolling stock manufacturing Train maintenance and depot operations Acoustic engineering and noise control HVAC and ventilation system design Brake system suppliers and integrators

Related Standards

  • ISO 11821 Acoustics — In-situ measurement of sound insulation of windows and façades
  • EN ISO 3095 Acoustics — Measurement of noise emitted by railbound vehicles
  • ISO 7235 Acoustics — Laboratory measurement of sound absorption coefficient of materials in impedance tubes

Other Test Methods

0 labs selected
Compare