EN ISO 7235:1995
(Main)Acoustics - Measurement procedures for ducted silencers - Insertion loss, flow noise and total pressure loss (ISO 7235:1991)
Acoustics - Measurement procedures for ducted silencers - Insertion loss, flow noise and total pressure loss (ISO 7235:1991)
This International Standard specifies the substitution method for determining the insertion loss of ducted silencers. It sets out requirements for determining: - the insertion loss, in frequency bands, of silencers with and without air flow; - the sound power level, in frequency bands, of the flow noise generated by silencers; - the total pressure loss of silencers with air flow. The measurement procedures are intended for laboratory measurements on silencers but may also be used for in situ measurements on silencers if the requirements of this International Standard can be met. This International Standard applies to silencers for ventilating air-conditioning systems which are usually connected to ducts or splitter absorbers mounted in ducts. Other duct elements, such as bends or T-connectors, may also be tested using this Intenational Standard. This International Standard does not apply to reactive silencers used for motor vehicles. [There is a note on the precision of the method]
Akustik - Messungen an Schalldämpfern in Kanälen - Einfügungsdämpfungsmaß, Strömungsgeräusch und Gesamtdruckverlust (ISO 7235:1991)
Diese internationale Norm beschreibt das Substitutionsverfahren zur Bestimmung des Dämpfungsverlustes von Schalldämperfn in Kanälen. Sie trifft Festlegungenzur Bestimmung - des Einfügungsdämpfungsmaßes von Schalldämpfern mit und ohne Luftstrom, gemessen in Frequenzbändern - des Schalleistungspegels des Strömungsgeräusches, verursacht durch Schalldämpfer, gemessen in Frequenzbändern - des Gesamtdruckverlustes von luftdurchströmten Schalldämpfern.
Acoustique - Méthodes de mesurage pour silencieux en conduit - Perte d'insertion, bruit d'écoulement et perte de pression totale (ISO 7235:1991)
Akustika - Merilni postopki za dušilnike za kanale - Dodano dušenje, hrup zaradi pretoka in padec totalnega tlaka (ISO 7235:1991)
General Information
- Status
- Withdrawn
- Publication Date
- 30-May-1995
- Withdrawal Date
- 31-Jul-2003
- Technical Committee
- CEN/TC 211 - Acuostics
- Drafting Committee
- CEN/TC 211 - Acuostics
- Current Stage
- 9960 - Withdrawal effective - Withdrawal
- Start Date
- 01-Aug-2003
- Completion Date
- 01-Aug-2003
- Directive
- 89/392/EEC - Machinery - Safety of machinery: general essential health and safety requirements
- Directive
- 98/37/EC - Machinery
Relations
- Effective Date
- 22-Dec-2008
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Frequently Asked Questions
EN ISO 7235:1995 is a standard published by the European Committee for Standardization (CEN). Its full title is "Acoustics - Measurement procedures for ducted silencers - Insertion loss, flow noise and total pressure loss (ISO 7235:1991)". This standard covers: This International Standard specifies the substitution method for determining the insertion loss of ducted silencers. It sets out requirements for determining: - the insertion loss, in frequency bands, of silencers with and without air flow; - the sound power level, in frequency bands, of the flow noise generated by silencers; - the total pressure loss of silencers with air flow. The measurement procedures are intended for laboratory measurements on silencers but may also be used for in situ measurements on silencers if the requirements of this International Standard can be met. This International Standard applies to silencers for ventilating air-conditioning systems which are usually connected to ducts or splitter absorbers mounted in ducts. Other duct elements, such as bends or T-connectors, may also be tested using this Intenational Standard. This International Standard does not apply to reactive silencers used for motor vehicles. [There is a note on the precision of the method]
This International Standard specifies the substitution method for determining the insertion loss of ducted silencers. It sets out requirements for determining: - the insertion loss, in frequency bands, of silencers with and without air flow; - the sound power level, in frequency bands, of the flow noise generated by silencers; - the total pressure loss of silencers with air flow. The measurement procedures are intended for laboratory measurements on silencers but may also be used for in situ measurements on silencers if the requirements of this International Standard can be met. This International Standard applies to silencers for ventilating air-conditioning systems which are usually connected to ducts or splitter absorbers mounted in ducts. Other duct elements, such as bends or T-connectors, may also be tested using this Intenational Standard. This International Standard does not apply to reactive silencers used for motor vehicles. [There is a note on the precision of the method]
EN ISO 7235:1995 is classified under the following ICS (International Classification for Standards) categories: 17.140.99 - Other standards related to acoustics. The ICS classification helps identify the subject area and facilitates finding related standards.
EN ISO 7235:1995 has the following relationships with other standards: It is inter standard links to EN ISO 7235:2003. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
EN ISO 7235:1995 is associated with the following European legislation: EU Directives/Regulations: 89/392/EEC, 98/37/EC; Standardization Mandates: M/BC/CEN/88/13. When a standard is cited in the Official Journal of the European Union, products manufactured in conformity with it benefit from a presumption of conformity with the essential requirements of the corresponding EU directive or regulation.
EN ISO 7235:1995 is available in PDF format for immediate download after purchase. The document can be added to your cart and obtained through the secure checkout process. Digital delivery ensures instant access to the complete standard document.
Standards Content (Sample)
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Akustika - Merilni postopki za dušilnike za kanale - Dodano dušenje, hrup zaradi pretoka in padec totalnega tlaka (ISO 7235:1991)Akustik - Messungen an Schalldämpfern in Kanälen - Einfügungsdämpfungsmaß, Strömungsgeräusch und Gesamtdruckverlust (ISO 7235:1991)Acoustique - Méthodes de mesurage pour silencieux en conduit - Perte d'insertion, bruit d'écoulement et perte de pression totale (ISO 7235:1991)Acoustics - Measurement procedures for ducted silencers - Insertion loss, flow noise and total pressure loss (ISO 7235:1991)91.140.30VLVWHPLVentilation and air-conditioning91.120.20L]RODFLMDAcoustics in building. Sound insulation17.140.01Acoustic measurements and noise abatement in generalICS:Ta slovenski standard je istoveten z:EN ISO 7235:1995SIST EN ISO 7235:1997en01-april-1997SIST EN ISO 7235:1997SLOVENSKI
STANDARD
ISO 7235:1991 (E) A-A Mineral wo01 Petforated sheet L L *Sd e - H=2000mm Figure D.4 - Example of two-sided anechoic termination [tested for d = 400 mm, d = 500 mm (see [13j) and d = 630 mm] 23 SIST EN ISO 7235:1997
ISO 7235:1991 (E) 1 2 3 4a 4b 5 6 7 8 9 10 Annex E (informative) Examples of measurement arrangements \ / 4 I 2 A 6 \ / V 5 ? /’ Loudspeaker unit Test duct in frontof the test silencer Transition eiements Test silencer Substitution duct Test duct behind the test silencer Transmission element 1 (as an alternative to 10) Reverberation room Microphone positions behind the test silencer (as alternatives to 9) Microphone positions in the reverberation room (as alternatives to 8) Anechoic termination (as an alternative to 6 and 7) Microphone b O0 O0 positions Figure E.1 - Examples of arrangements for the test facility for measuring the insertion loss of a silencer without air flow by the Substitution method 24 SIST EN ISO 7235:1997
ISO 7235:1991 (E) a) Arrangement for in-duct measurements 7 1 (’ I t I &-y,:gy, 11 12 IO 13 1‘2 13 11 b) Arrangement when using a reverberation room 1 Loudspeaker unit in the Source chamber 10 Fan (instaiied to generate either forward or reversed 2 Test duct in front of the test siiencer fiow relative to the direction of Sound propagation) 3 Transition eiements 11 Fan siiencers 4a Test siiencer 4b Substitution duct 12 Flexible duct sections 5 Test duct behind the test siiencer 13 Vibration insuiation 6 Transmission eiement, also used as fiow diffuser 14 Nozzie for measurement of fiow rate (alternative: 7 Reverberation room orifice or venturi nozzie) 8 Wind-shieided microphones
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