1、Designation: D2843 16Standard Test Method forDensity of Smoke from the Burning or Decomposition ofPlastics1This standard is issued under the fixed designation D2843; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last
2、revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S. Department of Defense.1. Scope*1.1 This fire-test-response test method
3、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 plastics under controlledconditions of combustion or decomposition. Cor
4、relation 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 constructed so that theflame and smoke is observable during the test.21.2 Du
5、ring the course of combustion, gases or vapors, orboth, are evolved that are potentially hazardous to personnel.Adequate precautions shall be taken to protect the operator.1.3 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationpurposes
6、 only.1.4 This standard is used to measure and describe theresponse of materials, products, or assemblies to heat andflame under controlled conditions, but does not by itselfincorporate all factors required for fire hazard or fire riskassessment of the materials, products, or assemblies underactual
7、fire conditions.1.5 Fire testing is inherently hazardous. Adequate safe-guards for personnel and property shall be employed inconducting these tests. Specific safety warning statements aregiven in 1.2 and 9.13.1.6 This standard does not purport to address all of thesafety problems, if any, associate
8、d 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 use.NOTE 1There is no known ISO equivalent to this standard.2. Referenced Documents2.1 ASTM Standards:3D618 P
9、ractice for Conditioning Plastics for TestingD883 Terminology Relating to PlasticsD1600 Terminology forAbbreviated Terms Relating to Plas-ticsE84 Test Method for Surface Burning Characteristics ofBuilding MaterialsE176 Terminology of Fire StandardsE662 Test Method for Specific Optical Density of Smo
10、keGenerated by Solid MaterialsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodE906 Test Method for Heat and Visible Smoke ReleaseRates for Materials and Products Using a ThermopileMethodE1354 Test Method for Heat and Visible Smoke ReleaseRates for Mate
11、rials and Products Using an Oxygen Con-sumption Calorimeter3. Terminology3.1 DefinitionsThe terminology used in this test method isin accordance with Terminologies D883 and D1600 (termsrelating to plastics) and Terminology E176 (terms relating tofire).4. Summary of Test Method4.1 The test specimen i
12、s 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 1 by14-in.) specimen is placed on supporting metal screen andburned in a laboratory test chamber (Fig. 1) under active flame1This test method is u
13、nder 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 May 1, 2016. Published May 2016. Originallyapproved in 1970. Last previous edition approved in 2010 as D2843 - 10. DOI:10.
14、1520/D2843-16.2Anonymous, “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 standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at
15、serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. U
16、nited States11. Specimen HolderA Stainless steel screenB Calcium-silicate sheetC Adjusting knobD Quench pan2. IgnitionA Burner 4. PhotometerB Propane tank A Visual system (exit sign)C Gas shut-off valve B Measuring systemD Pressure regulator adjustment 1 Light source and adjusting transformerE Press
17、ure indicator 2 Photronic cell and grid (to block stray light)F Burner-positioning knob 3 Meter (indicating percent of light absorbed)3. Cabinet (shown without door) 4 Temperature compensation (if required)A Hinges (door gasketed three sides) 5 Photocell temperature monitor (if required)B Vents (25-
18、mm (1-in.) high opening four sides) 6 Range changeC Blower (damper on mounting side) 5. TimerD Control (blower on when damper is open) A Indicator, 0 to 5 min (friction reset)FIG. 1 Schematic Diagram of Smoke ChamberD2843 162conditions using a propane burner operating at a pressure of276 kPa (40 psi
19、). The 300 by 300 by 790-mm (12 by 12 by31-in.) test chamber is instrumented 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-mm (1-in.) high ventil
20、ation openings around the bottom.4.2 The light-absorption data are plotted versus 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 hereinprescr
21、ibed are of considerable value in comparing the relativesmoke obscuration characteristics 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 2One study4suggest
22、ed that visual and instrumental observa-tions from this test compare well with the visual observations of the smokegenerated by plastic materials when added to a freely burning largeoutdoor fire.5.3 The usefulness of this test procedure is in its ability tomeasure the amount of smoke obscuration pro
23、duced in asimple, direct, and meaningful manner under the specifiedconditions. The degree of obscuration of vision by smokegenerated by combustibles is known to be affected by changesin quantity and form of material, humidity, draft, temperature,and oxygen supply.5.4 Safety PrecautionsProducts of co
24、mbustion are toxic.Care shall be taken to guard the operator from the effects ofproducts of combustion.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 consist of a 14-gage (B compensations shalltherefore be made. The photo
25、cell shall not be operated attemperatures 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 smoke accumulates to absorb 90 percent ofthe light beam, the meter shall be set to its basic sensitivity,
26、byany appropriate manner (for example, pressing a momentaryswitch, turning a dia, or automatically controlled by software).By doing this, the scale in the meter will then read from 90 to100 % absorption instead of reading from 0 to 100 % absorp-tion.6.1.5 Timing DeviceA timing device, such as a cloc
27、k,shall be used to indicate 15-s intervals. If the time intervals areaudibly marked it will be convenient for the operator to recordall observations. The timing device shall be reset at the start ofa test. The timing device shall start measuring when the burneris swung into test position.6.1.6 Plani
28、meterA 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.).Material thinner than 6.2 6 0.3 mm shall be tested by stacki
29、ngand forming a composite specimen 6.2 6 0.3 mm thick.Material thicker than 6.2 mm (14 in.) shall be tested bymachining the material down to a thickness of 6.2 6 0.3 mm.7.2 The specimens shall be sanded, machined, or die cut ina manner that produces a cut surface that is free fromprojecting fibers,
30、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) and 50 6 5 % relative humidity for not lessthan 40 h prior to test in accordance with Procedure A ofPractice D618, for those tests where conditio
31、ning is required.In cases of disagreement, the tolerances shall be 61C(61.8F) and 62 % relative humidity.8.2 Test ConditionsConduct tests in the standard labora-tory atmosphere of 23 6 2C (73.4 6 3.6F) and 50 6 5%T = Temperature-sensitive winding in or on meter case to increase in resistance in prop
32、ortion 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 = Potentiometer to calibrate total resistance of shunt to change meter sensitivity exactly by 10:1 ratio.FIG.
33、4 Smoke Density Test Chamber PhotometerD2843 165relative 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 the
34、test.9. Standard Procedure9.1 Turn on the photometer lamp, exit sign, and exhaustblower.9.2 Turn on the propane, immediately ignite the burner, andadjust the propane pressure to 276 kPa (40 psi).9.3 Set the temperature compensation as required.9.4 If possible, adjust the lamp control to 100 percent
35、lightabsorption (by blocking the light reaching the photocell with anopaque plate).9.5 Adjust the lamp control to zero percent light absorption.9.6 Lay the test specimen flat on the screen in such aposition that the burner flame will be directly under thespecimen when the burner is swung into positi
36、on.9.7 Ensure that the shallow pan of water is positioned belowthe specimen holder.9.8 Set the timer to zero.9.9 Shut off the exhaust blower, close the smoke chamberdoor, and immediately position the burner under the specimenand start the timer.9.10 If in a hood, shut off the hood fan and close the
37、hooddoor to within 50 mm (2 in.) of the bottom of the hood.9.11 Record the percent light absorbed at intervals as shortas possible, but not exceeding 15-s for 4 min.9.12 Record observations during the conduct of the test.Include the time it takes for the sample to burst into flame, thetime for flame
38、 extinguishment or specimen consumption, theobscuration of the exit sign by smoke accumulation, and anygeneral or unusual burning characteristics noted such asmelting, dripping, foaming, or charring.9.13 Upon completion of the test, turn on the exhaustblower to ventilate the combustion products from
39、 the chamber.9.14 Rotate the specimen holder rod and quench the burningspecimen in the shallow pan of water positioned below thespecimen holder.NOTE 5All products of combustion are toxic. Care shall be taken toguard the operator from the effects of these gases. This requires theexhaust blower to be
40、turned off and the hood damper to be closed duringthe test to prevent back draft (see 9.9). The ventilating fan in the hoodmust be turned on and the damper opened immediately after the test iscompleted before opening the hood door in order to remove any irritatingor toxic products of the test.9.15 O
41、pen 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 square of 6-mm (14-in.) thick calcium silicatefor the next test.9.16 Run all tests in triplicate.9.17 At the be
42、ginning 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 materials that drip, a second or auxiliary burner(with sepa
43、rate propane gas supply) shall be introduced into thechamber. See Fig. 5 and auxiliary burner parts list.10.2 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 tha
44、t its flame is directed at the center of the collectortray.10.3 To prevent movement of the burner during the test,place a lightweight, about 1100 g (2.5 lbs), on the aluminummounting plate (Item 12, Fig. 5).10.4 In all other respects the procedures of Section 9 shallbe followed.11. Optional Procedur
45、es11.1 Data acquisition hardware or a potentiometric recordercan be employed to record the output of the photocell versustime.11.2 With a suitably sensitive meter, more than one decadechange needs to be used to separate readings in the very densesmoke range.12. Treatment of Data12.1 Average the read
46、ings at 15-s intervals of light absorp-tion for the three specimens in each group. Plot the averagelight absorption against time. Fig. 2 is a sample curve.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 curve
47、 of the graph of average light absorption asa function of time, with the time axis ranging from 0 to 4minutes and the percentage light absorption axis ranging from0 to 100 %. The smoke density rating represents the totalamount of smoke present in the chamber for the 4-min timeinterval. Measure the s
48、moke density rating (SDR) by dividingthe area under the curve of light absorption versus time, by thetotal area of the graph and multiplying the result by 100.SDR = 100 (Area under Curve of Graph of Light Absorption vs. Time)/(Total Graph Area)NOTE 6ExampleIn the light absorption-time plot in Fig. 2
49、, 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 abscissa. The total graph areafor 4 min is found to be 16 000 mm2(24.80 in.2). The area under the curveis found to be 12 610 mm2(19.55 in.2). The smoke density rating, %, isthen computed as follows:Smoke density rating = (12610/16000 100 = 78.8(dimensions in millimetres)= (19.55/24.80) 100 = 78.8(dimensions in inches)D2843 16613. Report13.1 Report the following information:13.1.1 Identification of the material,13.1.2 Dimensions of
