1、NF EN 3475-602fvrier 2008Ce document est usage exclusif et non collectif des clients Saga Web.Toute mise en rseau, reproduction et rediffusion, sous quelque forme que ce soit,mme partielle, sont strictement interdites.This document is intended for the exclusive and non collective use of Saga Web cus
2、tomers.All network exploitation, reproduction and re-dissemination,even partial, whatever the form (hardcopy or other media), is strictly prohibited.Saga Web Pour SHANGHAI INTERNAT SCIENCE if a specific gas component exists, the indicating layer discolours due to chemical reactions. The length of th
3、e 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-specific electrodes in conne
4、ction 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 portions are optically measur
5、ed 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 described herein. 5.2 Probes f
6、or gas sampling The gases are sampled by means of three probes (internal diameter 6-8 mm) extending into the geometric center of the chamber. EN 3475-602:2007 (F)53.7bouteille dagitation rcipient spcial en verre pour la solution dabsorption 3.8prouvette tube en verre rempli dun ractif spcial destin
7、identifier quantitativement un composant gazeux spcifique 3.9molarit concentration dune solution exprime en nombre de moles (gr/masse molculaire) dun solut par litre de solution 3.10ISA (lonic Strength Adjuster) dispositif de rglage de la force ionique dune solution 3.11NTP (Normal Temperature and P
8、ressure) temprature et pression normales 3.12NBSNational Bureau of Standards, Washington 4 Principe de la mthode Le gaz fumigne produit dans les conditions des essais de densit de fume dcrits dans lEN 3475-601 est sujet analyse en fonction des composants gazeux examiner. La concentration de composan
9、ts gazeux non ractifs est dtermine laide de la procdure colorimtrique. Dans ce cas, on utilise des prouvettes remplies de ractivateur solide ; la couche indicatrice se dcolore par ractions chimiques lorsquelle est en prsence dun composant gazeux spcifique. La longueur du changement de couleur consti
10、tue une mesure de la concentration. La concentration de gaz ractifs est dtermine par potentiomtrie ; dans ce cas, on mesure les potentiels lectrochimiques qui peuvent tre convertis en concentrations ppm aprs avoir trac une courbe dtalonnage laide dlectrodes ioniques spcifiques raccordes une lectrode
11、 de rfrence spciale. 5 Prparation pour lanalyse 5.1 Gnralits Les prouvettes disposes verticalement dans une enceinte dessai ferme sont dcomposes chimiquement selon lEN 3475-601 par radiation thermique seule ou combine avec une flamme vive. Les quantits de fume rsultantes sont mesures optiquement sel
12、on cette mthode dessai. A cet gard, on prlve un chantillon de gaz un moment donn qui doit tre spcifi dans un plan dessai. Les gaz de dcomposition rsultant de la dgradation thermique sont dtermins quantitativement et qualitativement au moyen de la procdure analytique dcrite ici. 5.2 prouvettes pour p
13、rlvement de gaz Les gaz sont prlevs au moyen de trois prouvettes (diamtre interne de 6-8 mm) qui se prolongent dans le centre gomtrique de lenceinte. EN 3475-602:2007 (E) 6Resistant probe materials (such as polypropylene or PTFE) are to be selected due to the reactive behaviour of the halogenides. T
14、he 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 colorimetric “in situ“ mea
15、surement. 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 chamber and the plac
16、e 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, polyethylene; butadi
17、ene or silicone rubber types can also be used. PTFE 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 10 l to 15 l and a hig
18、h 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 to diffusion processe
19、s is negligible: Permeability of gas for O2 max. 20 cm3 NTP/m2 per 24 h N 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 processes are availab
20、le, 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 bag. The evacuation pre
21、ssure 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. The tank cover of 10 mm thick acrylic glass minimum is provided with a hole into which a quick-release coupling is to be installed gastight in order to connect
22、 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. EN 3475-602:2007 (F)6Choisir des matriaux dprouvette rsistants (comme le polypropylne ou PTFE) en raison du comportem
23、ent ractif des halognides. Les prouvettes doivent tre raccordes aux accessoires du tube et tre tanches aux gaz, en vue de raliser un prlvement de gaz sur le ct suprieur de lenceinte dessai. Les connexions non utilises doivent tre tanchises. Lune des prouvettes introduite dans lenceinte doit tre quip
24、e dun manchon en caoutchouc destin fixer le tube dessai pour prendre les mesures colorimtriques in situ . 5.3 Systme de prlvement de gaz pour les gaz non ractifs 5.3.1 Gnralits Les Figures 1 et 2 prsentent des montages de base de systmes de prlvement de gaz admissibles. 5.3.2 Tuyauterie pour le ball
25、on de gaz Une tuyauterie dune longueur maximale de 3 m doit tre installe entre le point de prlvement des gaz dans lenceinte et lemplacement servant capter les gaz. Si la tuyauterie de gaz ne peut tre chauffe, les tuyaux doivent tre isols thermiquement de faon viter la formation de condensation. Les
26、tuyaux doivent avoir une largeur interne de 6 mm 8 mm. Des tuyaux ou tuyauteries en plastique doivent tre utiliss et, en fonction de la pertinence, des types dlastomres en polythylne, butadine ou silicone peuvent aussi tre utiliss. Les PTFE sont recommands pour des exigences particulires relatives l
27、a rsistance la corrosion au moyen dune sollicitation thermique. Lextrmit du tuyau gaz oppos lenceinte doit tre quipe dun robinet cl. 5.3.3 Captation des gaz Des ballons dune capacit de 10 l 15 l et haute rsistance mcanique et chimique doivent tre utiliss pour recueillir les composants gazeux non rac
28、tifs analyser. Le polyfluorure de vinylidne faible diffusion gazeuse et permable aux vapeurs deau est recommand en tant que matriau mtallis de faon ce que le changement dans la composition du gaz d aux procds de diffusion soit ngligeable. Permabilit du gaz pour O2 max. 20 cm3 NTP/m2 par 24 h N max.
29、6 cm3 NTP/m2 par 24 h CO2 max. 140 cm3 NTP/m2 par 24 h Vapeur deau max. 13 g/m2 par 24 h En outre, les ballons utiliss doivent tre munis dun robinet cl. 5.3.4 Procds de captation des gaz Il existe deux procds de captation des gaz approuvs : captation au moyen dune pompe vide ou aspirante. Mthode vid
30、e : Un rservoir vide dune capacit minimale de 15 l est recommand pour collecter les composants gazeux analyser du ballon mentionn ci-dessus. Il convient de concevoir un rservoir suprieur de 5 l celui du volume du ballon. La pression dvacuation doit tre surveille au moyen dun calibre vide. Le rservoi
31、r vide doit tre muni dun clapet de ventilation et dune connexion pour la pompe vide. Le couvercle du rservoir en verre acrylique de 10 mm dpaisseur minimum est muni dun trou dans lequel un raccordement rapide, tanche aux gaz doit tre install et reli dun ct au ballon de gaz et de lautre ct au tuyau g
32、az. Une pompe vide crant le vide dans le rservoir et capable de remplir un ballon gaz en 20 s doit tre utilise. EN 3475-602:2007 (E) 7Procedure: The shut-off valve at the chamber is to be closed. The gas bag is to be connected to the gas sampling system via the quick-release coupling while ensuring
33、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 time of sampling, the stopcock at the test chamber (1) and the stopcock at the vacuum t
34、ank (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 valve (5) and the pump is switched off. The stopcock at the bag is closed and the filled ba
35、g 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 set-up of the equipment up to the suction pump is in accordance with 5.3.2. A manifold
36、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 20 s is to be used. Procedure: The shut-off valve (1) at the chamber is to be closed. The
37、 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 switched on and the gas bag is to be evacuated. The shut-off valve at the gas bag and the shut
38、-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 outlet and the shut-off valve at the gas bag is to be opened. At the time of sampling, the
39、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. After filling the gas bag, the shut-off valve (4), the gas bag valve and the chamber shu
40、t-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 “In situ” measurements for colorimetric determination of Hydrogenchloride (HCI) and Hydr
41、ogenfluoride (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 load must comply with the values specified by the manufacturer of the test tubes. A gas
42、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. The basic set-up is shown in Figure 3. Procedure: Prior to the commencement of the test,
43、 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. EN 3475-602:2007 (F)7Procdure : Le robinet darrt de lenceinte doit tre ferm. Le ballon gaz doit tre raccord au systme de prlvement de gaz via le raccord rapide tout en
44、sassurant que le robinet darrt du ballon de gaz est ouvert. Le rservoir doit tre ferm par un couvercle. La pompe vide doit tre active et les composants suivants doivent tre vids : tuyau gaz ; ballon de gaz ; rservoir vide. Lors du prlvement, le robinet darrt de lenceinte dessai (1) et celui du rserv
45、oir vide (2) sont ouverts. Les autres robinets darrts sont toujours ferms. Aprs le remplissage du ballon gaz, les deux robinets (1) et (2) de la tuyauterie de ravitaillement doivent tre ferms. Puis, le rservoir vide doit tre vid via le clapet de ventilation (5) et la pompe doit tre arrte. Le robinet
46、 darrt du ballon est ferm et le ballon rempli est dconnect du raccord rapide et immdiatement analys. Mthode de la pompe aspirante : La procdure suivante peut aussi tre utilise comme alternative la mthode vide pour remplir le ballon. Le montage de lquipement jusqu la pompe aspirante est conforme au 5.3.2. Une commande doit tre installe larrive et la sortie de la pompe comme indique dans la Figure 2. La commande doit tre utilise pour vider le ballon gaz et rincer le tuyau de gaz. Une pompe aspirante capable de remplir un ballon gaz en 20 s doit tre utilise. Proc
