AECMA PREN 3475-601-2006 Aerospace Series Cables Electrical Aircraft Use Test Methods Part 601 Smoke Density Edition P 2《航天系列 飞行器用的电缆试验方法.第601部分 烟密度》.pdf

1、ASD STANDARD NORME ASD ASD NORM prEN 3475-601 Edition P 2 September 2006 PUBLISHED BY THE AEROSPACE AND DEFENCE INDUSTRIES ASSOCIATION OF EUROPE - STANDARDIZATION Gulledelle 94 - B-1200 Brussels - Tel. + 32 2 775 8126 - Fax. + 32 2 763 3565 - www.asd-stan.org ICS: 49.060 Supersedes edition P 1 of No

2、vember 2001 Descriptors: Aerospace industry, aircraft equipment, electrical cable test ENGLISH VERSION Aerospace series Cables, electrical, aircraft use Test methods Part 601: Smoke density Srie arospatiale Cbles lectriques usage aronautique Mthodes dessais Partie 601 : Densit de fume Luft- und Raum

3、fahrt Elektrische Leitungen fr Luftfahrtverwendung Prfverfahren Teil 601: Rauchdichte This “Aerospace Series“ Prestandard has been drawn up under the responsibility of ASD-STAN (The AeroSpace and Defence Industries Association of Europe - Standardization). It is published for the needs of the Europe

4、an Aerospace Industry. It has been technically approved by the experts of the concerned Domain following member comments. Subsequent to the publication of this Prestandard, the technical content shall not be changed to an extent that interchangeability is affected, physically or functionally, withou

5、t re-identification of the standard. After examination and review by users and formal agreement of ASD-STAN, it will be submitted as a draft European Standard (prEN) to CEN (European Committee for Standardization) for formal vote and transformation to full European Standard (EN). The CEN national me

6、mbers have then to implement the EN at national level by giving the EN the status of a national standard and by withdrawing any national standards conflicting with the EN. Edition approved for publication 30 September 2006 Comments should be sent within six months after the date of publication to AS

7、D-STAN Electrical Domain Copyright 2006 by ASD-STAN Copyright Association Europeene des Constructeurs de Materiel Aerospatial Provided by IHS under license with AECMA Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-prEN 3475-601:20062 Contents Page Foreword .2 1 Sc

8、ope3 2 Terms and definitions .3 3 Principle of method.4 4 Test apparatus.4 4.1 Test chamber .4 4.2 Manometer .4 4.3 Pressure regulator 4 4.4 Chamber wall thermocouple 4 4.5 Electric power supply .5 4.6 Radiant heat furnace.5 4.7 Pilot burner system.6 4.8 Specimen holder .6 4.9 Support for radiant he

9、at furnace and specimen holder 7 4.10 Photometric system7 4.11 Exhaust hood.8 5 Test specimens .8 5.1 General .8 5.2 Number of specimens.9 5.3 Specimen length9 5.4 Specimen preparation.9 6 Conditioning 9 7 Check and maintenance of the test apparatus.9 7.1 Furnace protection9 7.2 Periodic calibration

10、 procedure 9 7.3 Chamber cleaning .11 7.4 Adjustment of test chamber.12 8 Test performance 12 9 Calculation .13 10 Requirements 14 11 Report .14 Foreword This standard was reviewed by the Domain Technical Coordinator of ASD-STANs Electrical Domain. After inquiries and votes carried out in accordance

11、 with the rules of ASD-STAN defined in ASD-STANs General Process Manual, this standard has received approval for Publication. Copyright Association Europeene des Constructeurs de Materiel Aerospatial Provided by IHS under license with AECMA Not for ResaleNo reproduction or networking permitted witho

12、ut license from IHS-,-,-prEN 3475-601:20063 1 Scope This test method 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 appli

13、cation. It is used for evaluation of insulation materials of electrical 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 i

14、n response to heat and flame under controlled laboratory conditions 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 tak

15、es into account all of the factors which are pertinent to an assessment 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 Ds Specific Optical Density, is a dimensionless measure of the amount of smoke

16、 produced per unit area by a material when it is burned 2.2 Dm maximum 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

17、 mode, the pyrolitic decomposition of the specimen under the influence of radiant heat only 2.5 T percent light transmission 2.6 Tt percent 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

18、 Copyright Association Europeene des Constructeurs de Materiel Aerospatial Provided by IHS under license with AECMA Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-prEN 3475-601:20064 3 Principle of method The specimens are vertically arranged in a closed test cham

19、ber 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 factor and the measured light obs

20、curation. 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 chamber door, chamber controls, flo

21、wmeters, 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 periodic cleaning. Commercially

22、 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 to provide convenient access fo

23、r 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 tests, there will be no leakage

24、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 chamber contents and a small positi

25、ve 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 800 cm2 shall be provided in a

26、n 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 Pressure regulator A pressure reg

27、ulator 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 of the chamber; the other end

28、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 junction secured to the geometr

29、ic centre of the inner rear wall panel of the chamber using an electrically insulating disk cover. Copyright Association Europeene des Constructeurs de Materiel Aerospatial Provided by IHS under license with AECMA Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-prE

30、N 3475-601:2006 5 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 fluctuations exceed 2,5 %, a constant voltage transformer shall be provided. 4.6 Radiant heat furnace 4.6.1 General An electric f

31、urnace and associated controlling devices shall be provided that is capable of providing a constant thermal flux density of (25 0,5) kW/m2 on the specimen surface. 4.6.2 Furnace construction The dimensions of the electric furnace are shown in Figure 2. The furnace shall be located centrally along th

32、e 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 chamber floor. 4.6.3 Heating element The heating element shall consist of a coiled wire capable of dissipating about 525 W. Wi

33、th 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 settings of voltage and current which is measured by the radiant heat output at the required level of (25 0,5) kW/m2 under stea

34、dystate 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 other means for monitoring the electrical input. It is recommended to use a digital voltmeter to monitor the furnace voltage outpu

35、t 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 of the radiant heat furnace. The heat flux density gauge shall be a circular foil type. Compressed air at a pressure of 0,10 M

36、Pa 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 accuracy 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

37、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-absorbing black paint. A voltmeter or other device which has a resolution of 0,01 mV and an accuracy of 0,3 % is required to monito

38、r the heat flux density gauge output. Copyright Association Europeene des Constructeurs de Materiel Aerospatial Provided by IHS under license with AECMA Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-prEN 3475-601:20066 4.7 Pilot burner system 4.7.1 Pilot burner T

39、he pilot burner shall be a straight tip burner with six tubes, as shown in 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 fab

40、ricated from stainless steel tubing having an outer diameter of 6,4 mm and 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

41、 the exposed surface of the specimen. 4.7.2 Pilot burner position The pilot 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 sur

42、face, see Figure 4. A fixture to accurately position the pilot burner is 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

43、 by mixing filtered oil-free air with 95 % minimum purity propane, and feeding 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 2

44、3 C and 1 013 hPa), and a propane flow rate equivalent to (50 3) cm3/min (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 an

45、d propane are mixed. 4.7.4 Igniter System An igniter system is recommended 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 supression and an equipment shielding must be a

46、pplied to have no interference with ability of data acquisition equipment 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 th

47、e specimen in place. 4.8.2 Specimen holder frame The specimen holder frame 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

48、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

49、be attached to the top and bottom of the holder frame. Copyright Association Europeene des Constructeurs de Materiel Aerospatial Provided by IHS under license with AECMA Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-prEN 3475-601:2006 7 4.8.3 Wire holder frame Holder frame is used to support the specimens. Construction details of the f