1、Designation: D 5485 05An American National StandardStandard Test Method forDetermining the Corrosive Effect of Combustion ProductsUsing the Cone Corrosimeter1This standard is issued under the fixed designation D 5485; the number immediately following the designation indicates the year oforiginal ado
2、ption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This fire-test-response standard measures the corrosiveeffect by loss
3、of metal from the combustion products ofmaterials, components, or products.1.2 This test method provides corrosion results of productand material specimens limited to a maximum size of 100 by100 mm in area and 50 mm thick.1.3 The results of this test method have not been investi-gated with respect t
4、o correlation to actual fires.1.4 This standard measures and describes the response ofmaterials, products, or assemblies to heat and flame undercontrolled conditions, but does not by itself incorporate allfactors required for fire hazard or fire risk assessment of thematerials, products, or assembli
5、es under actual fire conditions.1.4.1 Additional information regarding the targets, the testconditions, and test limitations are provided in the annex.1.5 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this
6、 standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. For specific hazardstatements, see Section 7.1.6 The values stated in SI units are the standard (seeIEEE/ASTM SI 10 .2. Referenced Documents2.1 ASTM Standards:2D 6
7、18 Practice for Conditioning Plastics for TestingD 1711 Terminology Relating to Electrical InsulationD6113 Test Method for Using a Cone Calorimeter toDetermine Fire-Test-Response Characteristics of Insulat-ing Materials Contained in Electrical or Optical FiberCablesE 176 Terminology of Fire Standard
8、sE 1354 Test Method for Heat and Visible Smoke ReleaseRates for Materials and Products Using an Oxygen Con-sumption CalorimeterIEEE/ASTM SI-10 Standard for Use of the InternationalSystem of Units (SI): The Modern Metric System2.2 Other Document:OSHA 191.1450 Occupational Exposure to Hazard Chemi-cal
9、s in Laboratories33. Terminology3.1 Definitions:3.1.1 For definitions of terms used in this test method, referto Terminologies E 176 and D 1711.3.2 Definitions of Terms Specific to This Standard:3.2.1 cone corrosimeter, nequipment used to determinecorrosion in this test method.3.2.2 corrosion-by-met
10、al-loss, nloss of metal of a targetexpressed as reduction of thickness of the target metal.3.2.3 exposure chamber, nenclosure in which a target isexposed to combustion products.3.2.4 heating flux, nincident power per unit area that isimposed externally from the heater on the specimen.3.2.4.1 Discuss
11、ionThe specimen, once ignited, is alsoheated by its own flame.3.2.5 sustained flaming, nexistence of flame on or overthe surface of the test specimen for periods of4sormore.3.2.5.1 DiscussionFlaming ignition of less than4sisidentified as transitory flaming or flashing.3.2.6 target, ndetector of know
12、n electrical resistancewhich can lose metal through a process of corrosion when it isexposed to combustion products.3.3 Symbols Specific to This Standard:3.3.1 A0initial corrosion instrument reading.3.3.2 A1corrosion instrument reading at the end of 1-hexposure to combustion products.3.3.3 A24corros
13、ion instrument reading at the end of 24 hin the environmental chamber.3.3.4 Ccorrosion of a target, nm.3.3.5 C1corrosion at the end of 1-h exposure to combus-tion products, nm.1This test method is under the jurisdiction of ASTM Committee D09 onElectrical and Electronic Insulating Materials and is th
14、e direct responsibility ofSubcommittee D09.21 on Fire Performance Standards.Current edition approved Sept. 1, 2005. Published October 2005. Originallyapproved in 1994. Last previous edition approved in 1999 as D 5485 99.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact
15、ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from Occupational Safety and Health Agency/U.S. Departmnet ofLabor.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C7
16、00, West Conshohocken, PA 19428-2959, United States.3.3.6 C24corrosion at the end of 24 h in the environmentalchamber, nm.3.3.7 mspecimen mass, g.3.3.8 mffinal specimen mass, g.3.3.9 miinitial specimen mass, g.3.3.10 m70average 70 % of the total mass loss, g.3.3.11 tdsampling time, s.3.3.12 Tetemper
17、ature of the gas in the exposure chamber,C.3.3.13 Vvolumetric sampling rate of combustion prod-ucts, m3/s.4. Summary of Test Method4.1 In this test method, a specimen is subjected to radiantheat. A spark igniter is used to ignite the combustible vapors.The products of decomposition or combustion are
18、 channeledthrough a funnel. A portion of the products continuously flowsthrough an exposure chamber which holds the corrosion targetsuntil the specimen has lost an average 70 % of the totalcombustible mass or for a period of 60 min, whichever is less.The corrosion of the target is determined by expo
19、sure of thetarget to combustion products for 1 h, followed by 24-hexposure of the target to a controlled humidity and temperatureenvironment in a separate chamber. The increase in electricalresistance of each target is monitored, and the reduction inthickness of the metal on the target is calculated
20、 from theincrease in electrical resistance. This reduction in thickness isreferred to as corrosion-by-metal-loss.4.2 This test method involves the use of a cone corrosimeteras described in Section 7 and shown in Fig. 1.4.3 Alternate equipment found suitable for this test methodis the cone calorimete
21、r (see Test Method E 1354), with theaddition of the gas sampling system described in this testmethod.5. Significance and Use5.1 The metal loss from corrosion is directly related to theincrease in electrical resistance of the target due to the decreasein conductive cross-sectional area.5.2 The relati
22、onship between resistance increase of metallictargets used in this test method and the amount of metal loss asreported by a uniform loss in thickness has not been deter-mined.5.3 This test method is used to determine the corrosiveeffect of combustion products from burning electrical insula-tions or
23、coverings or their constituent materials or components.Corrosion is determined by the reduction of thickness of themetal on standardized targets, as measured by electrical resis-tance. These targets are not necessarily representative of theintended end use.5.4 This test method is intended for use in
24、 electricalinsulations or coverings material and product evaluations, foradditional data to assist in design of electrical insulations orcoverings products, or for development and research of elec-trical insulations or coverings products.5.5 A value of the heating flux is selected to be relevant tot
25、he fire scenario being investigated (up to 100 kW/m2).Additional information for testing is given in A1.2.3.6. Interferences6.1 Discard the test data if any of the following occur:6.1.1 Leakage occurs between the sampling point and theexit of the exposure chamber which could cause a dilution ofgases
26、.6.1.2 The specimen swells sufficiently prior to ignition totouch the spark plug or swells into the plane of the heater baseplate during combustion.FIG. 1 Cone CorrosimeterD54850526.1.3 The specimen drips off the specimen holder or fallsout of the specimen holder such that the specimen is notsubject
27、ed to the test exposure conditions.6.1.4 There is highly localized corrosion of the target,indicating a defective target.6.1.5 There is visual degradation of the reference circuit bythe attack of combustion products on or under the protectivecoating.7. Apparatus7.1 General:7.1.1 This test method use
28、s the cone corrosimeter describedin 7.1.3. Alternatively, the cone calorimeter test equipment isacceptable provided that it is equipped with a gas samplingsystem as described in 7.8. If the cone calorimeter is used toassess the fire properties of insulating materials contained inelectrical or optica
29、l fiber cables, the test shall be conducted inaccordance with Test Method D6113, which was developedspecifically for that purpose.7.1.2 The dimensions of the cone corrosimeter specimenholder and additional equipment used in collection of gassamples are given in Figs. 1-8 and also stated in the follo
30、wingdescription.7.1.3 The cone corrosimeter consists of the following maincomponents: conical-shaped radiant electric heater; tempera-ture controller; load cell; electric ignition spark plug; heat-fluxgage; exhaust system; specimen holder; and the gas samplingsystem. Other essential elements needed
31、to measure corrosionare a corrosion target and a device to measure corrosion (see7.9). A general view of the cone corrosimeter is shown in Fig.1.7.2 Conical Heater:7.2.1 The active element of the heater consists of anelectrical heater rod, rated at 5000 W at 240 V, tightly woundinto the shape of a t
32、runcated cone (Fig. 2). The heater isencased on the outside with a double-wall stainless steel cone,and packed with a refractory fiber material of approximately100-kg/m3density.7.2.2 The heater is capable of producing heating flux on thesurface of the specimen of up to 100 kW/m2with a uniformityof 6
33、 2 % within the central 50 by 50-mm area of the specimen.7.2.3 The heating flux from the heater is held at a presetlevel by means of a temperature controller and three Type Kstainless-steel-sheathed thermocouples having an outside di-ameter of 1.5 to 1.6 mm with an unexposed hot junction.Alternative
34、ly, either 3-mm outside diameter sheathed thermo-couples with an exposed hot junction, or 1-mm outsidediameter sheathed thermocouples with an unexposed hot junc-tion are suitable. They are symmetrically disposed and incontact with, but not welded to, the heater element (see Fig. 2).The thermocouples
35、 are of equal length and wired in parallel tothe temperature controller.7.3 Temperature Controller:7.3.1 The temperature controller for the heater is to hold theelement temperature steady to within 6 2 C. A suitabletemperature controller system is a “3-term” controller (propor-tional, integral, and
36、derivative) with a thyristor unit capable ofswitching currents up to 25 A at 240 V.7.3.2 The controller has a temperature input range from 0 to1000 C; a set scale with a resolution of 2 C; and automaticcold junction compensation. The controller is equipped with asafety feature such that in the event
37、 of an open circuit in thethermocouple line, it will cause the temperature to fall to nearthe bottom of its range.7.3.3 The temperature controller uses a zero-crossing-typethyristor unit.7.3.4 The heater temperature is monitored by a meter with aresolution of 2 C.7.4 Exhaust System:7.4.1 The exhaust
38、-gas system consists of a high-temperaturecentrifugal exhaust blower, a hood, intake and exhaust ductsfor the fan, and an orifice plate flowmeter (Fig. 3).7.4.2 The flow rate is determined by measuring the differ-ential pressure across a sharp-edged orifice (57-mm insidediameter) in the exhaust stac
39、k, at least 350 mm downstreamfrom the fan.FIG. 2 Cross-Section View Through the HeaterD54850537.4.3 In other details, the geometry of the exhaust system isnot critical. Where necessary, small deviations from the rec-ommended dimensions given in Fig. 3 are allowed. Forexample, it is permissible for t
40、he inner diameter of the duct andthe orifice plate to be slightly different (tolerance: 6 2 mm).The location of the fan in Fig. 3 shall be between 900 and 1200mm downstream of the hood. Flow through the fan ensuresadequate mixing, which is essential to the test.7.5 Load CellThe general arrangement o
41、f the load cellwith the conical heater is shown in Fig. 4. Use a load cell withan accuracy of 0.1 g, a measuring range of at least 500 g, anda mechanical tare adjustment range of 3.5 kg.7.6 Specimen Holder and Mounting:7.6.1 A specimen holder consists of the bottom, the edgeframe, retaining pins, an
42、d wire grid as shown in Fig. 5. Thebottom is constructed from 2-mm nominal stainless steel andhas outside dimensions of 111 by 111 by 24-mm height (6 2mm). The grid is constructed from 1-mm nominal stainlesssteel and has dimensions of 109 by 109 mm (6 2 mm). Thegrid has 1-mm ribs and the openings in
43、 the center are 19 by 19mm (6 1 mm). The edge frame is constructed from 2-mmnominal stainless steel with outside dimensions of 116 by 116by 56-mm height (6 2 mm). The frame has an 8-mm lip on thetop to provide an opening of 100 by 100 mm on the top. Thereare two 3-mm (6 0.5 mm) diameter by 130-mm (6
44、 3 mm)long retaining pins to lock the test specimen in the edge frame.7.6.2 The bottom is lined with a layer of a low-density(nominal density 65 kg/m3) refractory fiber blanket withthickness of at least 13 mm. The distance between the bottomof the radiant heater and the top of the edge frame is adju
45、stedto 25 6 1 mm by using the sliding height adjustment (Fig. 2).7.7 Ignition Circuit:7.7.1 External ignitor is a spark plug powered from a 10-kVtransformer. The spark plug has a gap of 3 mm. The trans-former is of a type specifically designed for spark-ignition use.The transformer has an isolated (
46、ungrounded) secondary tominimize interference with the data-transmission lines. Theelectrode length and location of the spark plug is such that thespark gap is located 13 mm above the center of the specimen.7.8 Gas Sampling System:7.8.1 The gas sampling system consists of a conical funnel,stainless
47、steel tubing, electric heating tape, silicone rubbertubing, filter, flowmeter, exposure chamber, target supportstand, and pump. The general arrangement of the gas samplingsystem is shown in Fig. 1.7.8.2 FunnelThe funnel is a truncated cone constructedfrom stainless steel having a larger diameter of
48、173 6 5 mm,FIG. 3 Exhaust SystemFIG. 4 Exploded View of Load Cell and Cone Radiant HeaterD5485054a smaller diameter of 60 6 5 mm, and a height of 97 6 5 mm.It stands on 57 6 5-mm legs projecting from the largerdiameter end. The funnel is shown in Fig. 6.7.8.3 Rigid TubingA 6.3-mm (0.25-in.) outside
49、diameterby 675 6 75-mm long stainless steel tube draws a gas samplefrom the combustion stream. One end of the tube is bent withthe open end of the tube facing away from the specimensurface. The end of the tube is 255 6 10 mm from thespecimen surface. The other end of the rigid tube is connectedto flexible tubing. The arrangement of the rigid tube with thefunnel is shown in Fig. 6.7.8.4 Electric Heating TapeElectric heating tape is usedto maintain a minimum temperature of the rigid tubing.7.8.5 Flexible TubingThe flexible tubing consists of6.3-mm inside
