1、BRITISH STANDARD BS ISO 11907-3:1998 Plastics Smoke generation Determination of the corrosivity of fire effluents Part 3: Dynamic decomposition method using a travelling furnace ICS 13.220.40; 83.080.01BS ISO11907-3:1998 This British Standard, having been prepared under the direction of the Sector B
2、oard for Materials and Chemicals, was published under the authority of the Standards Board and comes into effect on 15June1998 BSI 05-1999 ISBN 0 580 29924 4 National foreword This British Standard reproduces verbatim ISO11907-3:1998 and implements it as the UK national standard. The UK participatio
3、n in its preparation was entrusted to Technical Committee PRI/26, Burning behaviour of plastics and rubbers, which has the responsibility to: aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change
4、, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international or Euro
5、pean publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the nece
6、ssary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, the I
7、SO title page, pages ii to iv, pages1 to16 and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Amendments issued since publication Amd. No. Date CommentsBS ISO 11907-3
8、:1998 BSI 05-1999 i Contents Page National foreword Inside front cover Foreword iii Text of ISO 11907-3 1ii blankBS ISO11907-3:1998 ii BSI 05-1999 Contents Page Foreword iii Introduction 1 1 Scope 1 2 Normative references 1 3 Definitions 2 4 Principle 2 5 Apparatus 2 6 Setting-up and calibration pro
9、cedures 4 7 Preparation of test samples 5 8 Procedure 6 9 Cleaning procedure 6 10 Expression of results 7 11 Precision 7 12 Test report 7 Annex A (normative) Alternative corrosion targets 11 Annex B (informative) Exposure in a flow-through chamber 13 Annex C (informative) Bibliography 16 Figure 1 Ty
10、pical decomposition apparatus and exposure of single corrosion target 7 Figure 2 Cuvette 8 Figure 3 Reference body 8 Figure 4 Copper printed wiring board 9 Figure 5 Water-cooled holder for corrosion targets 9 Figure 6 Segmentation with loose bulk materials 10 Figure A.1 Holder without cooling system
11、 13 Figure B.1 Typical flow-through exposure chamber 14 Figure B.2 Use of a flow-through exposure chamber Components of equipment assembled 15 Table 1 4 Table 2 5 Table A.1 Cleaning solutions 11 Table A.2 Parameters which may be used to characterize corrosive attack 12 Descriptors: Plastics, smoke g
12、eneration, combustion products, gaseous effluents, smoke, corrosion, tests, determination, corrosivity, dynamic tests.BS ISO 11907-3:1998 BSI 05-1999 iii Foreword ISO (the International Organization for Standardization) is a world-wide federation of national standards bodies (ISO member bodies). The
13、 work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-gove
14、rnmental, in liaison with ISO, also take part in the work.ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. Draft International Standards adopted by the technical committees are circulated to the member bodies for vo
15、ting. Publication as an International Standard requires approval by at least 75% of the member bodies casting a vote. International Standard11907-3 was prepared by Technical Committee ISO/TC61, Plastics, Subcommittee SC4, Burning behaviour. ISO11907 consists of the following parts, under the general
16、 title Plastics Smoke generation Determination of the corrosivity of fire effluents: Part 1: Guidance; Part 2: Static method; Part 3: Dynamic decomposition method using a travelling furnace; Part 4: Dynamic decomposition method using a conical radiant heater. Annex A forms an integral part of this p
17、art of ISO11907.Annex B and Annex C are for information only.iv blankBS ISO 11907-3:1998 BSI 05-1999 1 Introduction This method of test is one of a series being developed by ISO/TC61/SC4 concerning fire tests on plastics and other combustible materials to help assess the corrosivity of their fire ef
18、fluents. This test was developed in close connection with the work done in ISO/TC92/SC3. During a fire, hot and humid smoke may be carried throughout the building, and its various products may condense and settle down on the surfaces of walls, floors and e.g. machines and electronic equipment.In pri
19、nciple, smoke should always be expected to have a corrosive action, irrespective of the composition of the material. Corrosion is generally defined as decomposition, beginning at the surface, of metallic and non-metallic materials. The degree of damage, however, is specific both to the composition o
20、f the smoke and to the nature of the materials. The concentrations of the harmful substances depend on e.g. the ventilation and the scale of the fire, while the loss itself depends partly on factors unrelated to the actual fire, such as the air conditions in the rooms of the building, the hygroscopi
21、c behaviour of the construction materials and the nature, scale and timing of the rebuilding work. WARNINGS 1 Avoidance of misleading inferences This standard method of test should be used solely to measure and describe the properties of materials, products or systems in response to heat or flame un
22、der controlled laboratory conditions and should not be considered or used by itself for describing or appraising the fire hazard of materials, products or systems under actual fire conditions or as the sole source on which regulations pertaining to the corrosivity of fire effluents are based. 2 Avoi
23、dance of danger to test operators a) This test procedure involves combustion processes in which fire hazards may exist from combustion products. To avoid accidental leakage of hazardous combustion products into the surrounding atmosphere, the entire system (combustion apparatus and exposure system)
24、should be placed in a fume cupboard or under a canopy hood. b) The venting system shall be checked for proper operation before testing and shall discharge into an exhaust system with adequate capacity. c) As, in unfavourable circumstances, extremely rapid combustion or explosion can occur when the d
25、evice is in operation, a protective screen between the operator and the tube is recommended and, in addition, care should be taken to ensure that the gas outlet at the end of the quartz tube is of as large a diameter as possible. 1 Scope 1.1 This part of ISO11907 specifies a test method for generati
26、ng thermal decomposition products from plastic materials or products in an air stream and assessing the corrosive effects of these fire effluents on targets. It is not intended that the results be used to assess the corrosivity hazard of fire atmospheres. 1.2 It describes a dynamic decomposition tes
27、t method for the assessment of the corrosion damage of a standardized target by the change in its electrical resistance. 1.3 The decomposition model is suitable for simulating the main fire scenarios, such as a smouldering fire, a developing fire with flame formation, and a fully developed fire. The
28、 decomposition model enables a constant flow of smoke to be maintained throughout the exposure time. The decomposition model and exposure model enable the potential for a contribution to corrosivity to be estimated. 2 Normative references The following standards contain provisions which, through ref
29、erence in this text, constitute provisions of this part of ISO11907. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this part of ISO11907 are encouraged to investigate the possibility of applying the most recen
30、t editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. ISO 11907-1:1998, Plastics Smoke generation Determination of the corrosivity of fire effluents Part 1: Guidance. BS ISO11907-3:1998 2 BSI 05-1999 ISO 11907-2:1995, Plast
31、ics Smoke generation Determination of the corrosivity of fire effluents Part2: Static method. ISO 11907-4:1998, Plastics Smoke generation Determination of the corrosivity of fire effluents Part4: Dynamic decomposition method using a conical heater. 3 Definitions For the purposes of this part of ISO1
32、1907, the following definitions apply. 3.1 corrosion the reaction of a metallic material with its environment, resulting in a measurable change of the material and possibly in an impairment of the functioning of a metal part or of an entire system NOTEIn most cases, the reaction is electrochemical.
33、In others, however, it may be chemical (non- electrochemical) or physical. 3.2 corrosion damage the physical and/or chemical damage or impaired function caused by chemical action 3.3 fire effluent the totality of gases and/or aerosols (including suspended particles) created by combustion or pyrolysi
34、s 3.4 fire model a laboratory process, including the apparatus, the environment and the test procedure, intended to represent a certain phase of a fire 3.5 fire scenario a detailed description of conditions, including environmental, of one or more stages from before ignition to completion of combust
35、ion in an actual fire at a specific location, or in a real-scale simulation 3.6 corrosion target the sensor used to determine, under specified test conditions, the degree of corrosion damage NOTEThis sensor can be a product, a component or a reference material used to simulate them. 4 Principle An a
36、nnular furnace is set to a specified temperature and is moved over the test specimen located in a quartz cuvette inside a quartz glass tube through which air is passed at a specified flow rate. The conditions can be chosen to simulate a smouldering or developing fire as well as a developed fire (see
37、 ISO11907-1). A corrosion target consisting of a copper printed wiring board is exposed to the fire effluents and condensation is enhanced by using a cooling system. Condensed products react with the copper if they are corrosive, and the change in resistance of the target is used to denote the corro
38、sion hazard. 5 Apparatus 5.1 Combustion apparatus 5.1.1 The combustion apparatus consists of a quartz tube (see5.1.2), an annular furnace(see5.1.3), a flow meter(see5.1.4) and a cuvette(see5.1.5), generally arranged as shown inFigure 1 (see also6.1). 5.1.2 The quartz tube is mm long with an outer di
39、ameter of(40 1)mm and a wall thickness of (2 0,5)mm 5.1.3 The annular furnace, which encloses the quartz tube, is(100 1)mm long and able to traverse the quartz tube coaxially at a speed of (10 0,5)mm/min. NOTEFurnaces with the temperature distribution as required in6.2.3 are commercially available.
40、The power of the furnace shall be capable of maintaining the temperature required in6.2. 1 000 +300 0 BS ISO 11907-3:1998 BSI 05-1999 3 The furnace heater incorporates a thermocouple used to regulate the temperature of a reference body in conformance with6.2.3. 5.1.4 The flow meter is capable of mea
41、suring air flow per minute (fresh/room air) with an accuracy of 2%. 5.1.5 As sample holder, a cuvette is used. The cuvette is half a quartz tube with a wall thickness of (1,7 0,2)mm, a height of (15 1)mm and a length of mm. At each end of the cuvette there is a 2mm high lip(seeFigure 2). 5.1.6 An en
42、vironmental chamber capable of conditioning at (23 2) C and (50 5)% RH shall be provided. 5.1.7 An environmental chamber for post-test exposure of the target at (23 2) C and (75 5)% RH shall be provided. 5.2 Reference body The reference body consists of a strip, measuring (200 1)mm (5 0,1)mm (2 0,1)
43、mm, of austenitic stainless steel. In the middle of the reference body, there is a groove, typically1mm deep,1,2mm wide and10mm long, in which a thermocouple (NiCr-Ni or chromel-alumel) with1mm outside diameter is hard-soldered with high-melting silver. The reference body is supported on the undersi
44、de by two transverse rods of(1 0,1)mm diameter (seeFigure 3). In use, the reference body shall be connected to a temperature recorder providing readings to an accuracy of 0,5%. Before the first measurement, the reference body shall be annealed in air twice at a temperature of (550 50) C. 5.3 Timing
45、device The timing device shall be capable of recording elapsed time to the nearest second and shall be accurate to within15 s in1h. 5.4 Corrosion target The corrosion target shall consist of a copper printed wiring board (PWB) circuit (seeFigure 4) made by etching a copper-plated laminate base to pr
46、ovide36 conductor tracks each52mm long0,3mm wide and174m thick, at a spacing of0,3mm, on a laminated epoxy baseplate having the following characteristics Dimensions: Resistance: (8,0 0,5)7 5.5 Holder with cooling system The target holder shall enable one copper PWB to be cooled during the exposure,
47、as shown inFigure 5. It shall be made from a stainless-steel block. The cooling water shall flow through two horizontal bores which are connected by a vertical bore. The lower and upper openings of this bore shall be closed. The target shall be attached with two clamps, e.g. as shown inFigure 5. Unl
48、ess otherwise specified by the referring standard (in relation to a special test objective), normal tap water at (15 to 30) C shall be passed through the cooling system at a flow rate of approx.1,5l/min. 5.6 Alternative corrosion targets InAnnex A, examples of alternative corrosion targets are liste
49、d. If one of these targets is used, the procedure as described inAnnex A shall be followed. 5.7 Balance The balance shall be capable of weighing to an accuracy of 0,01g 5.8 Resistance-measuring device The device shall be capable of measuring resistance to an accuracy of 0,01 7 over the range (5 to 15) 7. 400 +10 0 30 00,3 mm60 0 0,3 mm 1,5 00,3 mm BS ISO11907-3:1998 4 BSI 05-1999 6 Setting-up and calibration procedures 6.1 Sit
