ASD-STAN PREN 2826-1995 Aerospace Series Burning Behaviour of Non Metallic Materials Under the Influence of Radiating Heat and Flames Determination of Gas Components in the Smoke (.pdf

1、 CEN PREN*:282b 95 3404589 0304764 745 AECMA STANDARD prEN 2826 NORME AECMA Edition P 1 AECMA NORM January 1995 DIT PAR LASSOCIATION EUROPENNE DES CONSTRUCTEURS DE MATRIEL AROSPATIAL Technopolis - 175, rue Jean-Jacques Rousseau - F-92138 Issy-les-Moulineaux Cedex - Tl. (i) 47.36.98.76 UDC : Descript

2、ors : ENGLISH VERSION Aerospace series Burning behaviour of non metallic materials under the influence of radiating heat and flames Determination of gas components in the smoke Srie arospatiale Luft- und Raumfahrt Comportement au feu Brandverhalten des matriaux non mtalliques sous laction de chaleur

3、 rayonnante et de flammes Dtermination des composants de gaz de fume nicht metallischer Werkstoffe unter Einwirkung von strahlender Wrme und Flammen Bestimmung von Rauchgaskomponenten This “Aerospace Series“ Prestandard has been drawn up under the responsibility of AECMA (Association Europenne des C

4、onstructeurs de Matriel Arospatial). It is published on green paper for the needs of AECMA-Members. It has been technically approved by the experts of the concerned Technical Committee following comment by the Member countries. Subsequent to the publication of this Prestandard, the technical content

5、 shall not be changed to an extent that interchangeability is affected, ph ysically or functionally, without re-identification of the standard. After examination and signature of the AECMA Standard Checking Centre (NPS) and formal agreement of the Official Services of the Member countries it will be

6、 submitted as a draft European Standard to CEN (European Committee for Standardization) for formal vote. Nota - Extra copies can be supplied by B.N.A.E. - Technopolis 54 - 199, rue Jean-Jacques Rousseau - 921 38 ISSY-LES-MOULINEAUX CEDEX C7 Chairman I Comments should be sent within six months after

7、the date of publication to I Edition approved for publication 1995-01 -31 AECMA Technopolis - 175, rue Jean-Jacques Rousseau 921 38 Issy-les-Moulineaux Cedex - FRANCE M. Bottrell CEN PRENSZ82b 95 3404589 01049b5 881 Page 3 prEN 2826 : 1995 1 Scope This standard defines a test method to determine the

8、 concentration of certain gas components due to pyrolitic decomposition of solid materials and composite materials under the influence of radiant heat only or with simultaneous flame application. NOTE : The gas components in the smoke are determined according to the specific environmental and test c

9、onditions defined in EN 2824 and this standard. No studies have been made up to now to determine whether the results can be transferred to different conditions, particularly to actual fire conditions. The inhalatory toxical risk and irritancy affect cannot be assessed by merely measuring the concent

10、ration of individual gas components in the smoke. The burning behaviour - and consequently the gas components in the smoke - of aerospace materials are not only influenced by the type of material but also to a large extent by the configuration, the specific surface and mass, the combination with oth

11、er materials, the means of joining as well as the processing technique. These influences shall be taken into account in the preparation of tests, the selection of test specimens and the interpretation of test results. 2 Normative references This European Standard incorporates by dated or undated ref

12、erence provisions from other publications. These normative references are cited at the appropriate places in the text and the publications are listed hereafter. For dated references, subsequent amendments to or revisions of any of these publications apply to this European Standard only when incorpor

13、ated in it by amendment or revision. For undated references the latest edition of the publication referred to applies. IS0 3261 EN 2824 Fire tests - Vocabulary Aerospace series - Burning behaviour of non metallic materials - Determination of smoke density and gas components in the smoke of materials

14、 under the influence of radiating heat and flames - Test equipment, apparatus and media 1) EN 2825 Aerospace series - Burning behaviour of non metallic materials - Determination of smoke density and gas components in the smoke of materials under the influence of radiating heat and flames - Determina

15、tion of smoke density 1) 3 Short description of the test method The specimens are vertically arranged in a closed test chamber according to EN 2824 and subjected to decomposition by radiant heat with or without flame application. During the test, gas samples are taken at specified intervals from the

16、 generated decomposition products to determine the concentration of selected components. The methods described in 3.1 and 3.3 are used to determine the gas components in the smoke. 3.1 test using colorimetric tubes or analyzed by wet analysis. The hydrogen chloride (HCI) taken from the test chamber

17、can be indicated directly during the 3.2 Hydrogen fluoride (HF) is measured by wet analysis. 3.3 isolation value ; they can be measured consecutively using colorimetric tubes. For determination of other gases, the fumes are collected in a plastic bag with a high gas- 1) Published as AECMA Prestandar

18、d at the date of publication of this standard Previous page is blank - - CEN PREN*Z826 95 3404589 0104966 718 Page 4 prEN 2826 : 1995 4 Definitions According to IS0 3261. 5 Designation EXAMPLE : Identity block I Description block TEST I EN2826A iT Number of this standard Code letter of test method (

19、see below) The letter code A indicates that the method is used to test a material in the Flaming mode only. The letter code B indicates that the method is used to test a material in both the Flaming mode and the Norm-Flaming mode. 6 Test equipment Testing shall be carried out in a test chamber accor

20、ding to EN 2824. 7 Specimens 7.1 Number of specimens According to EN 2824. 7.2 Conditioning According to EN 2824. 7.3 According to EN 2824. Dimensions and shape of specimens 7.4 Specimen mounting According to EN 2824. 8 Procedure The specimens conditioned according to EN 2824 are tested in line with

21、 the requirements of EN 2825, clause 8 ; gas samples are taken according to 8 and 10. Testing may be carried out concurrently to the determination of the smoke density according to EN 2825. When the specimens are being examined for gas components in the smoke only, the requirements specified for the

22、 adjustement of the optical system are not applicable. CEN PRENx2Zb 95 W 3i-104589 01049b 654 Page 5 prEN 2826 : 1995 9 Gas sampling and analysis The gas-sampling test set-up shall conform to EN 2824, figure 9. Unless otherwise specified, gas sampling shall be started at 4 min. If gas samples are ta

23、ken during the measurement of smoke, the smoke measurement values may be affected. The point of time indicated for the measurement means the beginning of the measurement, i. e. of the gas sampling. If the sampling period exceeds 40 s, this shall be noted separately in the test report. 9.1 The sampli

24、ng by means of plastic bags shall be carried out according to EN 2824, figure 9. Before starting the test, the sampling bag shall be evacuated. The bag is introduced into the vacuum chamber and then connected to the quick release coupling an the cover. The shut-off valve on the bag is opened and the

25、 tubing between test chamber and plastic sampling bag is evacuated. Then the vacuum chamber is evacuated to a pressure of 500 hPa. The sample is introduced into the test chamber and tested according to EN 2825. The chamber shut- off valve and the valve of the vacuum chamber are opened at the time re

26、quired for starting the gas measurement. After filling of the bag, both supply line valves shall be closed. The vacuum chamber shall be ventilated by means of valve 0 1). The shut-off valve 1) near the gas bag is closed, the bag is closed and disconnected from the cover. The measuring of the gases c

27、ontained in the plastic bag shall be carried out within 5 h. The measurement of SO2 shall be carried out within 5 min after the end of the sampling procedure. Sampling by means of plastic bags 9.2 Alternative sampling methods Alternatively to the sampling method of filling the bag in a vacuum chambe

28、r, other methods may also be appropriate, e.g. filling a sampling bag by a suitable pump. 9.3 Sampling to measure hydrogen chloride using colorimetric tubes is effected during the test directly from the test chamber by a dosing pump to EN 2824, clause 3.15. The sampling system and the dosing pump sh

29、all be checked for leakages. Direct sampling using a dosing pump 9.4 Handling of colorimetric tubes For handling and/or preparation of the test tubes the instructions of the manufacturer shall be observed. 9.5 Determination of halogens 9.5.1 Immediately before starting the test, the prepared HCI tes

30、t tube shall be fixed in the support of the probe in the test chamber. At the specified time after start of the test the supply line to the gas pump shall be opened by shut-off valve and the gas pump shall be switched on. The duration of the pumping operation shall be noted. Hydrogen chloride (using

31、 colorimetric tubes) I 1) See EN 2824, figure 9. Page 6 prEN 2826 : 1995 9.5.2 9.5.2.1 Measuring method The quantity of fluoride and chloride is measured by means of an ion specific fluoride or chloride electrode as indicator electrode and a reference electrode (e.g. silver chloride). The correspond

32、ing HF or HCI concentration is determined by means of a calibration curve. In order to plot this curve the electrode potentials of some NaF or NaCI buffer solutions with different molarity are determined and plotted in a calibration curve. Hydrogen fluoride and hydrogen chloride (potentiometric meas

33、urement ; wet analysis) NOTE : When measuring HCI, the presence of sulphur may influence the test results. In this case, Ni(NO3I2 shall be added to the test solution. Care shall be taken to maintain a pH value 3. Moreover, the electrode shall be recalibrated in the presence of Ni(NO3I2. The presence

34、 of bromide, too, substantially influences the measuring of HCI. If the material under test is suspected of containing bromide, this shall be verified by means of other measuring methods (e.g. ion chromatography). Products containing large quantities of HCN, NO, and NO2, can affect the amount of HCI

35、 measured. It is therefore necessary to adjust the solution to a pH value of 3. 9.5.2.2 Procedure The test Set-up shall conform to EN 2824. A scrubber according to EN 2824 is filled with 10 ml 0,l molarity CH3COONa, which has been adjusted to pH6, using glacial acetic acid. 1000 cm3 of the combustio

36、n gas to be tested are passed through this liquid at a flow rate of (400 k 50) mlhin. The scrubber location in the test chamber shall conform to EN 2824. The content of the scrubber is put into a 50 ml measuring flask and completed with distilled water, ionic strength adjuster and a buffer solution

37、suitable to bind potentially existing metal ions e.g. a complexing agent such as 1,2 cyclohexylenedinitrilotetra-acetic acid (monohydrate) up to the measuring mark. 9.5.2.3 Calculation The HF or HCI concentration in Vppm is calculated as follows : Vpp,(HF) = HF (molarity) x V (500ml) x 22,4 x 106 Qu

38、antity of absorbed combustion gas (1 OOOcm3) where : Vwm is the gas concentration in parts, per million ; HF (molarity) is the concentration of HF in molecular weight, per litres ; V is the volume of measuring flask, in millilitres, here 50 ml. The HF molarity (mol/l) is determined by inserting the

39、mV readout in the calibration curve. 9.6 Determination of other gases The measurement of other gases is effected by means of sampling bags. The dosing pump extension hose and the sampling bag filled with flue gas are connected by means of the quick release coupling. The corresponding colorimetric tu

40、be provided for the measurement of the gas to be tested is inserted into the connector of the extension hose. After opening of the shut-off valve on the sampling bag, testing is performed using the dosing pump. The suitable test tube as well as the number of strokes of the dosing pump shall be selec

41、ted according to the manufacturers instructions. CEN PRENx282b 95 m 3404589 0304969 427 m Page 7 prEN 2826 : 1995 9.7 vacuum pump. The discharged bag can be reused, however, it shall be free from soot deposits. From time to time the plastic shut-off valve on the bag shall be cleaned with isopropanol

42、. After having finished the test, the sampling bag shall be discharged with the aid of the 9.8 Sources of errors The notes of the test tube manufacturer regarding cross-sensitivities, permissible temperature range and other sources of error shall be observed. Some cleaning agents for the chamber wal

43、ls may affect the accuracy of the gas measurements. 10 Test report The test report (see annex A) shall include the following : 10.1 Complete description of the specimen material and the specimen construction (material designation, manufacturers identification, manufacturer/supplier, manufacturing ba

44、tch number, order number, construction, specimen thickness, density, etc.). 10.2 10.3 10.4 10.5 10.6 Period and conditions of specimen conditioning. Test conditions (with or without flame application). Number of tests performed. Indication of analytical method. Measuring results of the individual sm

45、oke gas components in ppm after the specified time and the arithmetic mean. 10.7 Particular observations during the test. 10.8 Date of testing. 10.9 Signature. I CEN PRENx282b 95 3404589 0304970 149 Page 8 prEN 2826 : 1995 Annex A (normative) Example for a test report on the determination of gas com

46、ponents in the smoke Material Material standard . . Technical specification . . Semi-finished product standard . Trade-mark of the product . Name and address of manufacturer . Name and address of supplier Purchaser . Order no . Delivery bill no . Date of manufacture . Manufacturing batch no Test rep

47、ort no of test laboratory 1) Specimen construction : Specimen conditioning : Analytical method : 1) Only to be filled in if the tests are carried out in the manufacturers laboratory. CEN PRENx2826 75 3404587 0104771 085 D Mean value I I Mean value Gas components in the smoke to be determined accordi

48、ng to material standard I I Specified values as per material standard after 4 min Mean value I Observations during testing : Mean value Notes : Mean value . (Place and date) Mean value Page 9 prEN 2826 : 1995 Table A.l - Testing without flame application application Specimen Measured values in ppm after 4 min values in ppm after 4 min Mean value I I Mean value I I . (Signature of the inspector) . (Stamp of the company and division) i