1、BRITISH STANDARDBS EN 3475-601:2007Aerospace series Cables, electrical, aircraft use Test methods Part 601: Smoke densityICS 49.060g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g
2、51g60g53g44g42g43g55g3g47g36g58BS EN 3475-601:2007This British Standard was published under the authority of the Standards Policy and Strategy Committee on 29 February 2008 BSI 2008ISBN 978 0 580 61214 5National forewordThis British Standard is the UK implementation of EN 3475-601:2007.The UK partic
3、ipation in its preparation was entrusted by Technical Committee ACE/6, Aerospace avionic electrical and fibre optic technology, to Panel ACE/6/-/2, Aerospace Cables.A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to
4、include all the necessary provisions of a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations.Amendments/corrigenda issued since publicationDate CommentsEUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN 3475-601
5、August 2007ICS 49.060English VersionAerospace series - Cables, electrical, aircraft use - Testmethods - Part 601: Smoke densitySrie arospatiale - Cbles lectriques usagearonautique - Mthodes dessais - Partie 601: Densit defumeLuft- und Raumfahrt - Elektrische Leitungen frLuftfahrzeuge - Prfverfahren
6、- Teil 601: RauchdichteThis European Standard was approved by CEN on 21 June 2007.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and b
7、ibliographical references concerning such nationalstandards may be obtained on application to the CEN Management Centre or to any CEN member.This European Standard exists in three official versions (English, French, German). A version in any other language made by translationunder the responsibility
8、 of a CEN member into its own language and notified to the CEN Management Centre has the same status as theofficial versions.CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,France, Germany, Greece, Hungary, Iceland, Irela
9、nd, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 B
10、-1050 Brussels 2007 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 3475-601:2007: E2 Contents Page Foreword3 1 Scope 4 2 Terms and definitions .4 3 Principle of method .5 4 Test apparatus .5 5 Test specimens9 6 Conditioning.10 7 Che
11、ck and maintenance of the test apparatus .10 8 Test performance.13 9 Calculation14 10 Requirements.15 11 Report .15 EN 3475-601:20073 Foreword This document (EN 3475-601:2007) has been prepared by the Aerospace and Defence Industries Association of Europe - Standardization (ASD-STAN). After enquirie
12、s and votes carried out in accordance with the rules of this Association, this Standard has received the approval of the National Associations and the Official Services of the member countries of ASD, prior to its presentation to CEN. This European Standard shall be given the status of a national st
13、andard, either by publication of an identical text or by endorsement, at the latest by February 2008, and conflicting national standards shall be withdrawn at the latest by February 2008. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent ri
14、ghts. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus,
15、Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. EN 3475-601:20074 1 Scope This test metho
16、d is intended for determination of the specific optical density of smoke generated by electrical wire/cable insulation materials due to pyrolitic decomposition under the influence of radiant heat only or with simultaneous flame application. It is used for evaluation of insulation materials of electr
17、ical wire/cable used in the interiors of aerospace vehicles but may be utilized in other applications as specified in applicable procurement documents. This standard should be used to measure and describe the properties of products in response to heat and flame under controlled laboratory conditions
18、 and should not be used to describe or appraise the fire hazard or fire risk of materials, products, or assemblies under actual fire conditions. However results of this test may be used as elements of a fire risk assessment which takes into account all of the factors which are pertinent to an assess
19、ment of the fire hazard of a particular end use. 2 Terms and definitions For the purposes of this document, the following terms and definitions apply. 2.1 DsSpecific Optical Density, is a dimensionless measure of the amount of smoke produced per unit area by a material when it is burned 2.2 Dmmaximu
20、m value of Ds, that occurs during the specified time of a test 2.3 F-mode Flaming mode, the pyrolitic decomposition of the specimen under the influence of radiant heat and with simultaneous flame application 2.4 NF-mode Non Flaming mode, the pyrolitic decomposition of the specimen under the influenc
21、e of radiant heat only 2.5 T percent light transmission 2.6 Ttpercent light transmission at the time t 2.7 Tm minimum percent light transmission 2.8 tDm time of the test in seconds at which the maximum optical smoke density occurs EN 3475-601:20075 3 Principle of method The specimens are vertically
22、arranged in a closed test chamber and subjected to decomposition by radiant heat only or with flame application. The smoke density is measured by means of the reduction of light transmission as smoke accumulates and expressed in terms of specific optical density which is derived from a geometric fac
23、tor and the measured light obscuration. 4 Test apparatus 4.1 Test chamber The test chamber shall be a square-cornered box with inside dimensions of (914 3) mm width, (610 3) mm depth, and (914 3) mm height. A typical test chamber is shown in Figure 1. The locations of size of items such as the chamb
24、er door, chamber controls, flowmeters, etc., is optional except as mandated in the following sections. The interior surfaces (except for the chamber door, vents, etc.) shall be porcelain-enameled metal, or equivalent coated metal that is resistant to chemical attack and corrosion, and suitable for p
25、eriodic cleaning. Commercially available panels of porcelain-enameled steel (interior surface) permanently laminated to a magnesia-insulation core and backed with galvanized steel (exterior surface) have been found acceptable. The chamber shall be equipped with a door such as indicated in Figure 1 t
26、o provide convenient access for changing test specimens, and for cleaning the chamber walls as required. The door shall have a viewing window to observe the chamber interior during a test, especially when any of the flamelets extinguish. The door shall have a seal so that when it is closed during te
27、sts, there will be no leakage of chamber contents. A small positive pressure can be developed and maintained inside the test chamber. An inlet-outlet vent for pressure equalization shall be provided. The vent shall have a seal so that when it is closed during tests, there will be no leakage of chamb
28、er contents and a small positive pressure can be developed and maintained inside the test chamber. To avoid an excessive increase of pressure in the chamber during testing an airtight safety disc is required, e.g. a sheet of aluminium foil of thickness not greater then 0,04 mm and a minimum area of
29、800 cm2shall be provided in an opening of the chamber floor. 4.2 Manometer A device such as a manometer or pressure transducer shall be provided to monitor chamber pressure and leakage. The device shall have a range up to 15 hPa, and be connected to a suitable port in the test chamber wall. 4.3 Pres
30、sure regulator A pressure regulator shall be provided that consists of an open water-filled bottle and a piece of tubing, not to exceed 3 050 mm in length, that has an inside diameter of at least 25 mm. One end of the tubing shall be connected to a port on the top or within 152 mm from the ceiling o
31、f the chamber; the other end of the tubing shall be held in position 102 mm below the water surface. 4.4 Chamber wall thermocouple The temperature of the test chamber wall shall be monitored by a thermocouple suitable for measuring a temperature of 35 C. The thermocouple shall be mounted with its ju
32、nction secured to the geometric centre of the inner rear wall panel of the chamber using an electrically insulating disk cover. EN 3475-601:20076 4.5 Electric power supply At least 650 W, single phase electric power shall be provided for the radiant heat furnace and accessories. Where line voltage f
33、luctuations exceed 2,5 %, a constant voltage transformer shall be provided. 4.6 Radiant heat furnace 4.6.1 General An electric furnace and associated controlling devices shall be provided that is capable of providing a constant thermal flux density of (25 0,5) kW/m2on the specimen surface. 4.6.2 Fur
34、nace construction The dimensions of the electric furnace are shown in Figure 2. The furnace shall be located centrally along the long axis of the chamber with the opening facing toward and approximately 305 mm form the right wall. The centerline of the furnace shall be approximately 197 mm above the
35、 chamber floor. 4.6.3 Heating element The heating element shall consist of a coiled wire capable of dissipating about 525 W. With the furnace installed, the heating element shall be positioned as shown in Figure 3. 4.6.4 Furnace control system The furnace control system shall be capable to hold the
36、settings of voltage and current which is measured by the radiant heat output at the required level of (25 0,5) kW/m2under steady-state conditions with the chamber door closed for at least 20 min. The control system shall consist of an AC solid state voltage or power controller and a voltmeter or oth
37、er means for monitoring the electrical input. It is recommended to use a digital voltmeter to monitor the furnace voltage output and a digital ampere-meter to monitor the furnace current. 4.6.5 Heat flux density gauge An air-cooled heat flux density gauge shall be provided for calibrating the output
38、 of the radiant heat furnace. The heat flux density gauge shall be a circular foil type. Compressed air at a pressure of 0,10 MPa to 0,21 MPa shall be provided to cool the heat flux density gauge. The body temperature of the heat flux density gauge shall be monitored with a thermometer having an acc
39、uracy of 1 C at 93 C in a 12,5 mm by 12,5 mm by 38 mm long brass or copper well drilled to accept the thermometer with a close fit. Silicone grease shall be used to provide good thermal contact. The circular receiving surface of the heat flux density gauge shall be spray-coated with an infrared-abso
40、rbing black paint. A voltmeter or other device which has a resolution of 0,01 mV and an accuracy of 0,3 % is required to monitor the heat flux density gauge output. EN 3475-601:20077 4.7 Pilot burner system 4.7.1 Pilot burner The pilot burner shall be a straight tip burner with six tubes, as shown i
41、n Figure 4. The six tubes shall be fabricated from stainless steel tubing having an outer diameter of 3,2 mm and a inner diameter of (1,4 0,025) mm. The six tubes shall be attached to a common manifold, as shown in Figure 4 fabricated from stainless steel tubing having an outer diameter of 6,4 mm an
42、d a wall thickness of 0,9 mm. One end of the manifold shall be closed, and the other end of the manifold be attached to a gas supply fitting in the chamber floor. All tubes of the pilot burner shall be directed perpendicular to the exposed surface of the specimen. 4.7.2 Pilot burner position The pil
43、ot burner shall be centred in front of and parallel to the specimen holder. The tips of the tubes shall be placed (6,4 1) mm above the lower opening of the specimen holder and (6,4 0,5) mm away from the face of the specimen surface, see Figure 4. A fixture to accurately position the pilot burner is
44、recommended to establish a precise pilot burner position for testing, and to facilitate accurate repositioning of pilot burner after removal and replacement. 4.7.3 Burner fuel The gas fuel for the pilot burner shall be prepared by mixing filtered oil-free air with 95 % minimum purity propane, and fe
45、eding the mixture to the pilot burner. Each gas shall be metered through separate, calibrated flowmeters and needle valves. The air-propane mixture shall consist of an air flow rate equivalent to (500 20) cm3/min (referred to 23 C and 1 013 hPa), and a propane flow rate equivalent to (50 3) cm3/min
46、(referred to 23 C and 1 013 hPa). The compressed air supply shall be fed to its flowmeter at (0,14 0,03) MPa, and the propane at (0,10 0,02) MPa. A backflow valve or a flame arrester should be provided in the lines where air and propane are mixed. 4.7.4 Igniter System An igniter system is recommende
47、d to relight the pilot burner flamlets to ensure that none of them extinguishes for more than 3 s during the test. If an electric sparking device is used, an appropriate method of suppression and an equipment shielding must be applied to have no interference with ability of data acquisition equipmen
48、t to accurately record data. 4.8 Specimen holder 4.8.1 General The specimen holder shall consist of a stainless steel frame, a wire holder frame, a backing made of insulation millboard and a spring and retaining rod to secure the specimen in place. 4.8.2 Specimen holder frame The specimen holder fra
49、me shall be fabricated of stainless steel sheet by bending and brazing (or spot welding) stainless steel sheet of (0,60 0,05) mm nominal thickness to conform in shape and dimension to Figure 6. The frame shall be at least 51 mm deep, and shall provide an exposed specimen surface that is nominally (65 1,5) mm by (65 1,5) mm. A trough to catch and retain dripping material shall be attached to the bottom front of the holder Guides to permit accurate centering of the exposed specimen area in front of the furnace opening shall be at
