1、BRITISH STANDARD BS ISO 11907-4:1998 Plastics Smoke generation Determination of the corrosivity of fire effluents Part 4: Dynamic decomposition method using a conical radiant heater ICS 13.220.40; 83.080.01BSISO 11907-4:1998 This British Standard, having been prepared under the directionof the Secto
2、r Board forMaterials and Chemicals, waspublished under the authorityof the Standards Boardand comes into effect on 15June 1998 BSI 06-1999 ISBN 0 580 29922 8 National foreword This British Standard reproduces verbatim ISO11907-4:1998 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, theIS
7、O title page, page ii, pages 1 to 18 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 CommentsBSISO 11907-4:1998 B
8、SI 06-1999 i Contents Page National foreword Inside front cover Foreword ii 1 Scope 1 2 Normative references 1 3 Definitions 1 4 Symbols specific to this test method 2 5 Principle 2 6 Apparatus 3 7 Test specimens 5 8 Conditioning 5 9 Calibration of apparatus 5 10 Equipment preparation 5 11 Specimen
9、preparation 5 12 Procedure 6 13 Validity of the test results 7 14 Calculation 7 15 Precision 7 16 Test report 7 Annex A (informative) Background information 8 Figure 1 Typical corrosion-testing device 10 Figure 2 Cross-section through a typical conical heater 11 Figure 3 Typical exhaust system 12 Fi
10、gure 4 Exploded view of a typical load cell and conical heater 13 Figure 5 Typical specimen holder assembly 14 Figure 6 Typical gas-sampling collection device 15 Figure 7 Typical exposure chamber 16 Figure 8 Typical corrosion target support stand and smoke baffle 17 Figure 9 Schematic drawing of typ
11、ical corrosion target 18ii blankBSISO 11907-4:1998 ii BSI 06-1999 Foreword ISO (the International Organization for Standardization) is a world-wide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical
12、 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-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with
13、 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 voting. Publication as an International Standard requires approval by at least75% of the
14、member bodies casting a vote. International Standard 11907-4 was prepared by Technical Committee ISO/TC61, Plastics, Subcommittee SC 4, Burning behaviour. ISO11907 consists of the following parts, under the general title Plastics Smoke generation Determination of the corrosivity of fire effluents: P
15、art 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 of this part of ISO11907 is for information only. Descriptors: Plastics, combustion products, smoke generation, gaseou
16、s effluents, smoke, tests, determination, corrosivity, dynamic tests.BSISO 11907-4:1998 BSI 06-1999 1 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
17、 under 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 corrosivity of fire effluents are based. 2 Avoid
18、ance of danger to test operators The test procedures involve high temperatures and combustion products. Therefore, conditions exist for burns, ignition of extraneous objects or clothing, and inhalation of combustion products. Use eye protection, and use protective gloves for insertion and removal of
19、 test specimens. Do not touch either the cone heater or the associated fixtures while hot, except with the use of protective gloves. Vent the combustion products flowing through the exposure chamber through a properly designed exhaust system. Vent the captured combustion products in a smoke hood at
20、the end of a test. Check the exhaust system for proper operation before testing, and discharge into a building exhaust system with adequate capacity. Make provisions for collecting and venting any combustion products that for whatever reason fail to be collected by the normal exhaust system of the a
21、pparatus. 1 Scope 1.1 This part of ISO11907 specifies a test method for measuring the corrosive effect, by loss of metal from a target, of the combustion effluents of plastic materials or products. 1.2 The test method is intended for the evaluation of materials or products, for additional data to as
22、sist in the design of products, and for development and research purposes. 1.3 The method provides corrosion results for plastic materials or product specimens limited to a maximum size of100mm 100mm in area. The results of this method have not been investigated with respect to correlation to actual
23、 fires. 1.4 The method measures the increase in electrical resistance of a metal circuit. Such increase is related to the decrease in conductive cross-sectional area resulting from the metal loss due to corrosion. 1.5 The method should be used to measure and describe the response of materials and/or
24、 products to heat and flame under controlled conditions but should not be used to describe or appraise the fire hazard or fire risk of materials under actual fire conditions. However, results of this test may be used as elements of a fire hazard or risk assessment as they relate to a particular end
25、use. 2 Normative references The following standards contain provisions which, through reference 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
26、part of ISO11907 are encouraged to investigate the possibility of applying the most recent editions of the standards listed below. Members of IEC and ISO maintain registers of currently valid International Standards. ISO 5660-1:1993, Fire tests Reaction to Fire Part 1: Rate of heat release from buil
27、ding products (Cone calorimeter method). ISO 11907-1:1998, Plastics Smoke generation Determination of the corrosivity of fire effluents Part 1: Guidance. 3 Definitions For the purposes of this part of ISO11907, the following definitions apply. 3.1 corrosion the reaction of a metallic material with i
28、ts 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. In others, however, it may be chemical (non-electrochemical) or physical. 3.2 corrosion damage
29、the physical and/or chemical damage or impaired function caused by chemical action 3.3 corrosion by metal loss the loss of metal on a target, expressed as reduction in thickness of the target metal 3.4 corrosion testing device equipment used to determine corrosion in this standardBSISO 11907-4:1998
30、2 BSI 06-1999 3.5 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. 3.6 irradiance (at a point on a surface) the radiant flux incident on an infin
31、itesimally small element of the surface containing the point, divided by the area of that element NOTEThe specimen, once ignited, is also heated by its own flame. 3.7 exposure chamber the enclosure in which a target is exposed to combustion products 3.8 environmental chamber the enclosure used to ex
32、pose the targets to high humidity and temperature after the exposure to combustion products 3.9 sustained flaming existence of a flame on or over the surface of the specimen for a minimum period of time (over 10 s) NOTEFor flaming of less than10s, the flaming is considered transitory or flashing. 3.
33、10 fire effluent the totality of gases and/or aerosols (including suspended particles) created by combustion or pyrolysis 3.11 fire model a laboratory process, including the apparatus, the environment and the test procedure, intended to represent a certain phase of a fire 3.12 fire scenario a detail
34、ed description of conditions, including environmental, of one or more stages from before ignition to completion of combustion in an actual fire at a specific location, or in a real-scale simulation 4 Symbols specific to this test method 5 Principle 5.1 This test method is used to determine the corro
35、sive effect of combustion products from burning plastic materials. Corrosion is determined by the reduction in thickness of the metal on standardized targets, which is directly related to the increase in electrical resistance of the target due to the decrease in conductive cross-sectional area. Thes
36、e targets are not necessarily representative of the intended end use. 5.2 The test is conducted in two parts. In the first part, two weight loss tests are conducted by exposing the test specimen to a recommended irradiance of50kW/m 2 , or to other heating fluxes up to100kW/m 2relevant to particular
37、scenarios. A spark igniter is used to ignite the combustible vapours. The combustible mass loss is determined as the average mass loss of the two tests. A 0 Initial electrical resistance of the corrosion target, 7. A 1 Electrical resistance of the corrosion target at the end of 1 hour exposure to co
38、mbustion products, 7. A 24 Electrical resistance of the corrosion target at the end of 24 hours in the environmental chamber, 7. C Corrosion of a target, nm. C 1 Corrosion of a target at the end of 1 hour exposure to combustion products, nm. C 24 Corrosion of a target at the end of 24 hours in the e
39、nvironmental chamber, nm. m Specimen mass, g. m i Initial specimen mass, g. m f Final specimen mass, g. m 70 70% of the total mass loss, g. t d Sampling time, s. q v Volumetric sampling rate of combustion products, m 3 /s.BSISO 11907-4:1998 BSI 06-1999 3 In the second part, the specimen is subjected
40、 to the same irradiance as before. The products of decomposition or combustion are channeled through a funnel, and a portion of the products continuously flows through an exposure chamber, which holds the corrosion targets, until the specimen has lost70% of the loss measured in the two preliminary t
41、ests. The corrosion of the corrosion target is determined by exposure of the target to combustion products for1hour, followed by24hour exposure of the corrosion target to a controlled humidity and temperature environment in a separate chamber. The increase in electrical resistance of each target is
42、monitored and the reduction in thickness of the metal on the target is calculated from the increase in electrical resistance. This reduction in thickness is referred to as corrosion by metal loss. 5.3 Additional guidance for testing is given in Annex A and in ISO11907-1. 6 Apparatus 6.1 Corrosion-te
43、sting device 6.1.1 General The corrosion-testing device consists of the following main components: a cone-shaped radiant electric heater, a temperature controller, an exhaust system, a specimen holder and mounting, an ignition circuit, a load cell, a heat flux meter and a gas-sampling system as deta
44、iled below. A general view of the corrosion-testing device is shown in Figure 1 and typical dimensions are shown in Figure 1 to Figure 8. The cone calorimeter test equipment described in ISO5660-1 may be used as a corrosion-testing device, provided that it is equipped with a gas-sampling system as d
45、escribed in6.1.9. 6.1.2 Conical heater The active element of the heater consists of an electrical heater rod, rated at5000W/240V, tightly wound into the shape of a truncated cone (seeFigure 2). The heater is encased on the outside with a double-walled stainless-steel cone, and packed with a refracto
46、ry fibre material of approximately100kg/m 3density. The heater is capable of producing an irradiance on the surface of the specimen of up to100kW/m 2with a uniformity of 2% within the central50mm 50mm area of the specimen. The irradiance from the heater is held at a preset level by means of a temper
47、ature controller and three type K stainless-steel-sheathed thermocouples having an outside diameter of1,5mm to1,6mm and with an unexposed hot junction. Alternatively, either3mm outside diameter sheathed thermocouples with an exposed hot junction or1mm outside diameter sheathed thermocouples with an
48、unexposed hot junction are suitable. They are symmetrically disposed and in contact with, but not welded to, the heater element (seeFigure 2). The thermocouples are of equal length and wired in parallel to the temperature controller. 6.1.3 Temperature controller The temperature controller, which sha
49、ll be capable of holding the heating-element temperature steady to within 2 C, has a temperature input range of0to1000 C, a set scale with a resolution of 2 C, and automatic cold junction compensation. The controller uses a zero crossing type thyristor unit and is equipped with a safety feature such that, in the event of an open circuit in the thermocouple line, it will cause the temperature to fall to near the bottom of its range. NOTEA suitable temperature controller system is a “3-term” controller (proportional, integr
