1、Designation: D 2843 99 (Reapproved 2004)e1Standard Test Method forDensity of Smoke from the Burning or Decomposition ofPlastics1This standard is issued under the fixed designation D 2843; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revis
2、ion, 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.This standard has been approved for use by agencies of the Department of Defense.e1NOTEEditorially changed Note
3、1 in December 2004.1. Scope*1.1 This fire-test-response test method covers a laboratoryprocedure for measuring and observing the relative amounts ofsmoke obscuration produced by the burning or decompositionof plastics. It is intended to be used for measuring thesmoke-producing characteristics of pla
4、stics under controlledconditions of combustion or decomposition. Correlation withother fire conditions is not implied. The measurements aremade in terms of the loss of light transmission through acollected volume of smoke produced under controlled, stan-dardized conditions. The apparatus is construc
5、ted so that theflame and smoke can be observed during the test.21.2 WarningDuring the course of combustion, gases orvapors, or both, are evolved that may be hazardous to person-nel. Adequate precautions should be taken to protect theoperator.1.3 The values stated in SI units are to be regarded as th
6、estandard. The values given in brackets are for informationpurposes only.1.4 This standard should be used to measure and describethe response of materials, products, or assemblies to heat andflame under controlled laboratory conditions and should not beused to describe or appraise the fire-hazard or
7、 fire-risk ofmaterials, products, or assemblies under actual fire conditions.However, results of this test may be used as elements of afire-hazard assessment or a fire risk assessment which takesinto account all of the factors which are pertinent to anassessment of the fire hazard or fire-risk of a
8、particular enduse.1.5 This standard does not purport to address all of thesafety problems, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to u
9、se. Specific warningstatements are given in 1.2 and 9.11.NOTE 1There is no known ISO equivalent to this standard.2. Referenced Documents2.1 ASTM Standards:3D 618 Practice for Conditioning Plastics for TestingD 883 Terminology Relating to PlasticsD 1600 Terminology for Abbreviated Terms Relating toPl
10、asticsE84 Test Method for Surface Burning Characteristics ofBuilding MaterialsE 176 Terminology for Fire StandardsE 662 Test Method for Specific Optical Density of SmokeGenerated by Solid MaterialsE 691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodE 906
11、Test Method for Heat and Visible Smoke ReleaseRates for Materials and ProductsE 1354 Test Method for Heat and Visible Smoke ReleaseRates for Materials and Products Using an Oxygen Con-sumption Colorimeter3. Terminology3.1 DefinitionsThe terminology used in this test method isin accordance with Termi
12、nologies D 883 and D 1600 (termsrelating to plastics) and Terminology E 176 (terms relating tofire).4. Summary of Test Method4.1 The test specimen is exposed to flame for the duration ofthe test, and the smoke is substantially trapped in the chamberin which combustion occurs. A 25 by 25 by 6-mm 1 by
13、 1 by14-in. specimen is placed on supporting metal screen and1This test method is under the jurisdiction of ASTM Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.30 on Thermal Properties-(Section D20.30.03).Current edition approved December 1, 2004. Published January 200
14、5. Originallyapproved in 1970. Last previous edition approved in 2004 as D 2843 - 99 (2004).2Anonymous, “A Method of Measuring Smoke Density,” NFPA Quarterly,QNFPA, Vol 57, January 1964, p. 276. Reprint NFPA Q57-9. Available from NFPA,60 Batterymarch St., Boston, MA 02110.3For referenced ASTM standa
15、rds, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM Intern
16、ational, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.burned in a laboratory test chamber (Fig. 1) under active flameconditions using a propane burner operating at a pressure of276 kPa 40 psi. The 300 by 300 by 790-mm 12 by 12 by31-in. test chamber is instrumen
17、ted with a light source,photoelectric cell, and meter to measure light absorptionhorizontally across the 300-mm 12-in. light beam path. Thechamber is closed during the 4-min test period except for the25-m 1-in. high ventilation openings around the bottom.4.2 The light-absorption data are plotted ver
18、sus time. Atypical plot is shown in Fig. 2. Two indexes are used to rate thematerial: the maximum smoke produced and the smoke-densityrating.5. Significance and Use5.1 Tests made on a material under conditions hereinprescribed can be of considerable value in comparing therelative smoke obscuration c
19、haracteristics of plastics.5.2 This test method serves to determine the extent to whichplastic materials are likely to smoke under conditions of activeburning and decomposition in the presence of flame.NOTE 2The visual and instrumental observations from this testcompare well with the visual observat
20、ions of the smoke generated byplastic materials when added to a freely burning large outdoor fire.45.3 The usefulness of this test procedure is in its ability tomeasure the amount of smoke obscuration produced in asimple, direct, and meaningful manner under the specifiedconditions. The degree of obs
21、curation of vision by smokegenerated by combustibles can be substantially affected bychanges in quantity and form of material, humidity, draft,temperature, and oxygen supply.6. Apparatus6.1 The smoke chamber shall be constructed essentially asshown in Fig. 1.56.1.1 Chamber:6.1.1.1 The chamber shall
22、consist of a 14-gage (B compensations shall therefore be made.NOTE 5Photocell manufacturers recommend operating the photocellat temperatures not exceeding 50C.6.1.4.4 The meter shall have two ranges. The range changeshall be accomplished by shunting the meter to one tenth of itssensitivity. When smo
23、ke accumulates to absorb 90 percent ofthe light beam, a momentary switch shall be depressed return-ing the meter to its basic sensitivity. By doing this the meterscale will then read from 90 to 100 % instead of 0 to 100 %.6.1.5 Timing DeviceA clock to indicate 15-s intervalsshall be used. If the tim
24、e intervals are audibly marked it will beconvenient for the operator to record his observations. A clutchshall be used to reset the clock at the start of a test. The blockshall be coupled to the burner-positioning device and it shallstart when the burner is swung into test position.6.1.6 PlanimeterA
25、 planimeter or other suitable meansshall be used for measuring the area under the light-absorptioncurve.7. Test Specimen7.1 The standard specimen shall be 25.4 6 0.3 by 25.4 60.3 by 6.2 6 0.3 mm 1 6 0.01 by 1 6 0.01 by14 6 0.01 in.Thicknesses other than 6.2 mm 14 in. may be used and theirsize must b
26、e reported with the smoke density values (Note 6).Material thinner than 6.2 mm 14 in. may be tested, either inits normal use thickness, or by stacking and forming acomposite specimen approximately 6.2 mm 14 in. thick.Material thicker than 6.2 mm 14 in. may be tested either in itsnormal use thickness
27、 or by machining the material down to athickness of 6.2 mm 14 in.NOTE 6If specimens other than the standard specimen are to be used,cooperating laboratories should agree upon preparation procedures anddimensions of the specimen. The results in such cases may vary from theresults obtained with the st
28、andard specimen.7.2 The specimens shall be sanded, machined, or die cut ina manner that produces a cut surface that is free fromprojecting fibers, chips, and ridges.7.3 The test sample shall consist of three specimens.8. Conditioning8.1 ConditioningCondition the test specimens at 23 62C 73.4 6 3.6F
29、and 50 6 5 % relative humidity for not lessthan 40 h prior to test in accordance with Procedure A ofPractice D 618, for those tests where conditioning is required.In cases of disagreement, the tolerances shall be 61C61.8F and 62 % relative humidity.8.2 Test ConditionsConduct tests in the standard la
30、bora-tory atmosphere of 23 6 2C 73.4 6 3.6F and 50 6 5%relative humidity, unless otherwise specified in the test meth-ods or in this test method. In cases of disagreement, thetolerances shall be 1C 61.8F and 62 % relative humidity.8.3 Tests shall be conducted in a hood that has a window forobserving
31、 the test.T = Temperature-sensitive winding in or on meter case to increase in resistance in proportion to increase in meter resistance with temperature.R = Potentiometer with calibrated scale to reduce resistance in proportion to decrease in photocell output with rise in temperature.C = Potentiomet
32、er to calibrate total resistance of shunt to change meter sensitivity exactly by 10:1 ratio.FIG. 4 Smoke Density Test Chamber PhotometerD 2843 99 (2004)e159. Standard Procedure9.1 Turn on the photometer lamp, exit sign, and exhaustblower.9.2 Turn on the propane, ignite the burner, and adjust theprop
33、ane pressure to 276 kPa 40 psi. WarningDo not fail tolight the burner immediately.9.3 Set the temperature compensation.9.4 Adjust the lamp control to zero percent light absorption.9.5 Lay the test specimen flat on the screen in such aposition that the burner flame will be directly under thespecimen
34、when the burner is swung into position.9.6 Set the timer to zero.9.7 Shut off the exhaust blower, close the smoke chamberdoor, and immediately position the burner under the specimenand start the timer.9.8 If in a hood, shut off the hood fan and close the hooddoor to within 50 mm 2 in. of the bottom
35、of the hood.9.9 Record the percent light absorbed at 15-s intervals for 4min.9.10 Record observations during the conduct of the test.Include the time it takes for the sample to burst into flame, thetime for flame extinguishment or specimen consumption, theobscuration of the exit sign by smoke accumu
36、lation, and anygeneral or unusual burning characteristics noted such asmelting, dripping, foaming, or charring.9.11 Upon completion of the test, turn on the exhaustblower to ventilate the combustion products from the chamber.(WarningIt should be noted that for some materials theproducts of burning m
37、ay be toxic, and care should be taken toguard the operator from the effects of these gases. Theventilating fan in the hood should be turned on and the damperopened immediately after the test is completed before openingthe hood door in order to remove any irritating products of thetest. The exhaust f
38、an is turned off and the hood damper closedduring the test to prevent back draft.)9.12 Open the door and clean the combustion deposits fromthe photometer, exit sign, and door glass with detergent andwater. Burn off any material remaining on the screen or replacethe screen and asbestos square for the
39、 next test.9.13 Run all tests in triplicate.9.14 At the beginning of each series or at least once a day,check the light absorption of the meter against a calibratedneutral filter of approximately 50 % absorption. Check the100 % absorption point against an opaque plate.10. Special Procedure10.1 For m
40、aterials which drip excessively, a second orauxiliary burner (with separate propane gas supply) shall beintroduced into the chamber. See Fig. 5 and auxiliary burnerparts list.10.2 The asbestos sheet (Item 1B of Fig. 1) shall be replacedwith a stainless steel collector tray. This tray has a slight ta
41、perto permit the drippings to collect at the bottom. See item 11 ofFig. 5 and parts list for auxiliary burner.10.3 The auxiliary burner shall be ignited at the same timethe standard burner is ignited. The auxiliary burner shall beoperated at 138 kPa 20 psi and it shall be positioned in sucha manner
42、that its flame is directed at the center of the collectortray.NOTE 7It may be helpful to place a lightweight, about 1100 g 2.5lbs, on the aluminum mounting plate (Item 12, Fig. 5) to preventmovement of the burner during the test.10.4 In all other respects the procedures of Section 8 shallbe followed
43、.11. Optional Procedures11.1 The output of the photocell may be recorded versustime on an appropriate graphic recorder.11.2 With a suitably sensitive meter, more than one decadechange may be used to separate readings in the very densesmoke range.12. Treatment of Data12.1 Average the readings at 15-s
44、 intervals of light absorp-tion for the three specimens in each group. Plot the averagelight absorption against time on linear paper. Fig. 2 is a samplecurve.12.2 Read the maximum smoke density as the highest pointon the curve.12.3 Determine the total smoke produced by measuring thearea under the cu
45、rve. The smoke density rating represents thetotal amount of smoke present in the chamber for the 4-mintime interval. Measure the total smoke produced by the areaunder the curve of light absorption versus time, divided by thetotal area of the graph, 0-4 min 0-100 % light absorption, times100.NOTE 8Ex
46、ampleIn the light absorption-time plot in Fig. 2, the plothas been made using 10 mm 0.39 in. equal to 10 % as the ordinate and10 mm 0.39 in. equal to 0.25 min as the absicca. The graph area for 4min is found to be 16 000 mm224.80 in.2. The area under the curve isfound to be 12 610 mm219.55 in.2. The
47、 smoke density rating, %, is thencomputed as follows:Smoke density rating= (12610/16000 3 100 = 78.8(dimensions in millimetres)= (19.55/24.80) 3 100 = 78.8(dimensions in inches)13. Report13.1 Report the following information:13.1.1 Identification of the material,13.1.2 Dimensions of the specimen,13.
48、1.3 Readings of light absorption at 15-s intervals foreach test and average,13.1.4 Plots of average light absorption versus time,13.1.5 Maximum smoke density in percent light absorption,13.1.6 Area in percent under the light absorption-time curve(smoke density rating),13.1.7 Observations on behavior
49、 of material,13.1.8 Observations on obscurement of exit sign,13.1.9 The details of any departure from the specificationsof the method for testing, and13.1.10 The caveat contained in 1.4 herein shall be incor-porated in its entirety in the report issued.D 2843 99 (2004)e1614. Precision and Bias (Standard Procedure)614.1 Table 1 is based on a round robin completed in 1998 inaccordance with Practice E 691, involving five materials testedby six laboratories. For each material, all the samples wereprepared at
