1、ASD STANDARD NORME ASD ASD NORM prEN 3475-602 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 602: Toxicity Srie arospatiale Cbles lectriques usage aronautique Mthodes dessais Partie 602 : Toxicit Luft- und Raumfahrt Elektr
3、ische Leitungen fr Luftfahrtverwendung Prfverfahren Teil 602: Giftigkeit 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 European Aerospace
4、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, without re-identifi
5、cation 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 members have th
6、en 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 ASD-STAN Electr
7、ical Domain Copyright 2006 by ASD-STAN prEN 3475-602:20062 Contents Page Foreword . 2 1 Scope 3 2 Normative references 3 3 Terms and definitions. 3 4 Principle of method. 4 5 Preparation for analysis . 4 5.1 General . 4 5.2 Probes for gas sampling 5 5.3 Gas sampling system for non-reactive gases 5 5
8、.4 Gas sampling for reactive Gases 6 5.5 Checking of sampling systems . 7 6 Analytical chemistry . 8 6.1 Colorimetric method of measurement 8 6.2 Potentiometric method of measurement (Wet Analysis) for determination of the halogenides F, Cl. 8 7 Requirements 10 8 Report. 10 Foreword This standard wa
9、s reviewed by the Domain Technical Coordinator of ASD-STANs Electrical Domain. After inquiries and votes carried out in accordance with the rules of ASD-STAN defined in ASD-STANs General Process Manual, this standard has received approval for Publication. prEN 3475-602:2006 3 1 Scope This test metho
10、d is intended for use in determining the concentration of specific gas components of smoke released by cable insulation materials. This test method should be used to measure and describe the properties of cable insulation materials in response to heat and flame under controlled laboratory conditions
11、. This standard should be used to measure and describe the properties of products in 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. Howev
12、er 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 assessment of the fire hazard of a particular end use. 2 Normative references The following referenced documents are indispensable for the application of th
13、is document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 3475-601, Aerospace series Cables, electrical, aircraft use Test methods Part 601: Smoke density. 1) 3 Terms and definitions
14、 For the purposes of this standard, the following terms and definitions apply. 3.1 ppm parts per million, concentration 3.2 colorimetry analytical procedure using colour comparison 3.3 potentiometry determination of ionic concentration by electrochemical measurements 3.4 in situ at the site (in this
15、 case: in the NBS chamber) 3.5 halogenides the group of chlorides, fluorides, bromides and iodides They have a strong electrophilic character and are therefore very reactive. 1) Published as ASD Prestandard at the date of publication of this standard. prEN 3475-602:20064 3.6 absorbent liquid suitabl
16、e for collecting gas components 3.7 impinger bottle special glass vessel for the absorption solution 3.8 test tube glass tube filled with a special reagent for quantitative identification of a specific gas component 3.9 molarity concentration of a solution expressed as mol (gr/molecular weight) of s
17、olute per litre of solution 3.10 ISA lonic Strength Adjuster 3.11 NTP Normal Temperature and Pressure 3.12 NBS National Bureau of Standards, Washington 4 Principle of method The smoke gas produced under the conditions of the smoke density test described in EN 3475-601 is subjected to an analysis dep
18、ending on the gas components to be investigated. The concentration of non-reactive gas components is determined by means of the colorimetric procedure. In this case, test tubes filled with a solid reagent are used; if a specific gas component exists, the indicating layer discolours due to chemical r
19、eactions. The length of the colour change is a measure for the concentration. The concentration of the reactive gases is determined by potentiometry; in this case, electrochemical potentials which can be converted into ppm concentrations after plotting of a calibration curve are measured with ion-sp
20、ecific electrodes in connection with a special reference electrode. 5 Preparation for analysis 5.1 General The specimens arranged vertically in a closed test chamber, are chemically decomposed according to EN 3475-601 by thermal radiation alone or in combination with flaming. The resulting smoke por
21、tions are optically measured according to this test method. In this connection, a gas sample is taken at a time, which has to specified in a test plan. The decomposition gases resulting from thermal degradation are determined qualitatively and quantitatively by means of the analytical procedure desc
22、ribed herein. prEN 3475-602:2006 5 5.2 Probes for gas sampling The gases are sampled by means of three probes (internal diameter 6-8 mm) extending into the geometric center of the chamber. Resistant probe materials (such as polypropylene or PTFE) are to be selected due to the reactive behaviour of t
23、he halogenides. The probes are to be connected gastight to the tube fittings for gas sampling at the upper side of the test chamber. Connections not used are to be sealed. One of the probes inserted into the chamber is to be provided with a rubber sleeve for attachment of the test tube for colorimet
24、ric “in situ“ measurement. 5.3 Gas sampling system for non-reactive gases 5.3.1 General Figures 1 and 2 show the basic set-ups for allowable gas sampling systems. 5.3.2 Pipe system for the gas bag A pipe system with a maximum length of 3 m is to be installed between the gas sampling point at the cha
25、mber and the place of gas collection. If the gas pipe system cannot be heated, thermal insulation of the pipes is to be provided so as to avoid the formation of condensates. The pipes must have an inner width of 6 mm to 8 mm. Plastic hoses or pipes must be used and, depending on the suitability, pol
26、yethylene; butadiene or silicone rubber types can also be used. PTFE and are recommended for special requirements with regard to corrosion resistance with temperature load. The gas pipe end facing the chamber is to be provided with a stopcock. 5.3.3 Collection of gases Foil bags with a capacity of 1
27、0 l to 15 l and a high mechanical and chemical resistance are to be used for the collection of the non-reactive gas components to be analyzed. Polyvinylidene fluoride with low gaseous diffusion and water vapour permeability is recommended as foil material so that a change in the gas composition due
28、to diffusion processes is negligible: Permeability of gas for O2 max. 20 cm3 NTP/m2 per 24 h N2 max. 6 cm3 NTP/m2 per 24 h CO2 max. 140 cm3 NTP/m2 per 24 h Water vapour max. 13 g/m2 per 24 h Furthermore, the bags used must be provided with a stopcock. 5.3.4 Gas collection Two approved gas collection
29、 processes are available, collection by means of vacuum or by suction pump. Vacuum method: A vacuum tank with a minimum capacity of 15 l is recommended for collecting the gas components to be analyzed in the above-stated foil bag. The design of the tank should be 5 l greater then the volume of the b
30、ag. The evacuation pressure is to be monitored by a vacuum gauge. The vacuum tank is to be provided with a ventilation valve and a connection for the vacuum pump. prEN 3475-602:20066 The tank cover of 10 mm thick acrylic glass minimum is provided with a hole into which a quick-release coupling is to
31、 be installed gastight in order to connect the gas bag, on the one side, with the gas pipe, on the other side. A vacuum pump producing a vacuum in the tank capable of filling a gas bag according to within 20 s is to be used. Procedure: The shut-off valve at the chamber is to be closed. The gas bag i
32、s to be connected to the gas sampling system via the quick-release coupling while ensuring that the shut-off valve at the gas bag is open. The tank is to be sealed with a cover. The vacuum pump is to be switched on and the following components are to be evacuated: gas pipe gas bag vacuum tank At the
33、 time of sampling, the stopcock at the test chamber (1) and the stopcock at the vacuum tank (2) are opened. The other shut-off valves are still closed. After filling of the gas bag, both stopcocks (1) and (2) in the supply line are to be closed. Then the vacuum tank is vented via the ventilation val
34、ve (5) and the pump is switched off. The stopcock at the bag is closed and the filled bag is disconnected from the quick-release coupling and to be immediately analyzed. Suction pump method: The following procedure can also be used as an alternative to the vacuum method for filling the foil bag. The
35、 set-up of the equipment up to the suction pump is in accordance with 5.3.2. A manifold is to be installed at the inlet and outlet of the pump as shown in Figure 2. The manifold is used to vent the gas bag and to flush the gas pipe. The suction pump capable of filling a gas bag according to within 2
36、0 s is to be used. Procedure: The shut-off valve (1) at the chamber is to be closed. The gas bag is to be connected to the coupling (8) in front of the pump manifold. The shut-off valves (2) and (4) are to be opened. The shut-off valve at the gas bag is to be opened. The suction pump is to be switch
37、ed on and the gas bag is to be evacuated. The shut-off valve at the gas bag and the shut-off valve (2) are to be closed and the pump is to be switched off. The shut-off valve (3) is opened and the shut-off valve (4) is closed. The closed gas bag is to be connected to the coupling (6) at the pump out
38、let and the shut-off valve at the gas bag is to be opened. At the time of sampling, the shut-off valve (1) at the test chamber is opened. The suction pump is to be switched on. After 30 s at the earliest, the shut-off valve (3) is closed and the shut-off valve (4) in front of the gas bag is opened.
39、After filling the gas bag, the shut-off valve (4), the gas bag valve and the chamber shut-off valve (1) are all to be closed. The suction pump is to be switched off. The filled bag is disconnected from the suction pump and the contents immediately analyzed. 5.4 Gas sampling for reactive Gases 5.4.1
40、“In situ” measurements for colorimetric determination of Hydrogenchloride (HCI) and Hydrogenfluoride (HF) The samples for measuring the hydrogen fluoride and chloride with colorimetric test tubes are taken directly from test chamber by means of a suction pump. The suction capacity of the pump under
41、load must comply with the values specified by the manufacturer of the test tubes. A gas pipe of the material and diameter recommended in 5.3.2 connects the probe to the suction pump. A shut-off valve is to be installed in front of the suction pump as well as a volumetric flowmeter for flow control.
42、The basic set-up is shown in Figure 3. prEN 3475-602:2006 7 Procedure: Prior to the commencement of the test, both tips of the test tube are broken off with a tube opener and inserted into the probe with the arrow pointing towards the pump. The volumetric suction flow at the suction pump is selected
43、 and checked as specified by the manufacturer for the test tube. A certain quantity of the gas sample to be tested, which was specified by the manufacturer, is now sucked through the test tube at the set volumetric suction flow. The existence of the specific gas results in instantaneous discoloratio
44、n. Observe for cross- sensitivities which are explained in the relevant directions for use. 5.4.2 “In situ” measurement for potentiometric determination of Hydrogenfluoride (HF) and Hydrogenbromide (HBr) and Hydrogenchlorine(HCI) The equipment set-up must comply with Figure 3. The samples for measur
45、ing the halogenides by means of an absorption solution are taken directly from the test chamber by means of a suction pump. The suction capacity of the pump should not exceed 2 000 cm3/min. A gas pipe of the material and diameter recommended in 5.3.2 connects the probe to the suction pump. A shut-of
46、f valve is to be installed at the side facing the chamber. A washing bottle for cleaning the gases, a dosaging valve and a volumetric flowmeter for monitoring and correcting the flow are to be installed in the pipe system to the pump. An impinger bottle as per Figure 4 is filled 20 ml of a 0.5 molar
47、 sodium acetate solution which was set to a pH value of 6 using 10 % acid (15 cm3 98 % acetic acid/I). Prior to commencement of the test, the impinger bottle is to be fixed and aligned in the chamber so that the sample gas inlet opening extends into the center of the chamber. It must be ensured that
48、 the stopcock is closed during the test. The suction pump is to be switched on for sampling and the shut-off valve at the chamber is to be opened. 1 000 cm3 of the smoke gas to be tested are passed through the receiver with a flow rate of 1 800 cm3/min maximum. 5.5 Checking of sampling systems 5.5.1
49、 Gas pipe systems The following work is to be performed on each day of testing prior to the first test: Check leakage of gas pipe systems. Check probe for sucking off non-reactive gases for contamination and clean, if necessary. 5.5.2 Delivery systems On each day of testing, prior to commencement of the test, the delivery systems are to be checked for proper function and capacity. Prior to each measuring series, the suction pump is to be subjected to a leakage test with an unopened test tube for measuring of the smoke gas components out of the gas bag. 5.5
