1、Designation: D 3523 92 (Reapproved 2007)An American National StandardStandard Test Method forSpontaneous Heating Values of Liquids and Solids(Differential Mackey Test)1This standard is issued under the fixed designation D 3523; the number immediately following the designation indicates the year ofor
2、iginal adoption 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 test method covers the non-adiabatic determinationof th
3、e spontaneous heating values (SHV) of liquids and solids.It is applicable to substances that are not completely volatile atthe test temperature. Spontaneous heating values obtained bythis test method are qualitative indications of the degree ofself-heating that may be expected to occur upon exposure
4、 ofthe sample to air at the test temperature.1.2 Values obtained by this method are applicable to liquidsand solids supported on cellulosic surfaces. They are notapplicable to liquids on metal surfaces, on contaminatedsurfaces, or at pressures above atmospheric.1.3 Spontaneous heating values determi
5、ned by the presenttest method are regarded only as qualitative measurements ofself-heating which occurs under the conditions of the test. Thetest method does not purport to produce a quantitative measureof the enthalpy of reaction of the sample with air at a given testtemperature. Such data can be o
6、btained by the use of anadiabatic calorimeter. The existence, under the test conditions,of a positive temperature difference between the sample andthe reference is evidence of a thermochemical reaction in thesample.1.4 The magnitude of the measured temperature differenceis a semiquantitative indicat
7、ion of the enthalpy and rate of thatreaction. Since factors such as heat loss from the sample to thebath and quenching of the reaction due to too rapid consump-tion of oxygen affect the amount and duration of the measuredheat effect, care must be taken not to attribute too muchquantitative significa
8、nce to the test results. It is sufficient, forthe purpose of this test, to determine whether or not the sampleis capable of undergoing a self-heating reaction of sufficientmagnitude and rapidity to produce a detectable thermal effect.The spontaneous heating value (SHV) can be lower than thetest temp
9、erature. A negative result does not preclude sponta-neous heating initiating at a temperature higher than the testtemperature.1.5 This standard should be used to measure and describethe response of materials, products, or assemblies to heat andflame under controlled conditions and should not be used
10、 todescribe or appraise the fire-hazard or fire-risk of materials,products, or assemblies under actual fire conditions. However,results of this test may be used as elements of a fire-hazardassessment or a fire-risk assessment which takes into accountall of the factors which are pertinent to an asses
11、sment of the firehazard or fire risk of a particular end use.1.6 The values stated in SI units are to be regarded as thestandard. In cases where materials, products or equipment areavailable in inch-pound units only, SI units are omitted.1.7 This standard does not purport to address all of thesafety
12、 concerns, 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 use.2. Referenced Documents2.1 ASTM Standards:2D 1193 Specification for Reagent W
13、ater3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 spontaneous heating value (SHV)the maximumamount by which the temperature of the sample exceeds that ofthe reference when exposed at a given temperature in thestandard apparatus.3.2 Symbols:tS= temperature of sample side at a
14、ny time during test,K,tR= temperature of reference side at time tSis measured,K,TS= maximum temperature of sample chamber duringtest, K,1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.11 on Engi
15、neering Sciences of High Performance Fluids and Solids.Current edition approved May 1, 2007. Published June 2007. Originallyapproved in 1976. Last previous edition approved in 2002 as D 3523 92 (2002).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Servi
16、ce at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.TR= temperature of reference chamber measured
17、 at sametime that TSis measured, K,Dt = tS tR,DT = TS TR,BR= equilibrium temperature of reference side duringblank run, K,BS= equilibrium temperature of sample side duringblank run, K,DTB= BS BR= instrumental blank,DtC= Dt (BSBR)=Dt DTB, andDTC= DT (BS BR)=DT DTB= spontaneous heatingvalue.4. Summary
18、 of Test Method4.1 The sample is supported on surgical gauze and placed ina heated chamber which is open to the air at the top. Thetemperature of the sample, thus prepared, is compared to thatof an equal reference quantity of surgical gauze contained in anidentical chamber. The amount by which the t
19、emperature of thesample exceeds that of the reference is taken as an index of thespontaneous heating value of the sample. Tests may beconducted for durations of 4 to 72 h or longer if desired.4.1.1 Any convenient, inert, fibrous substrate of adequateabsorbency may be substituted for surgical gauze a
20、s required.Any such substitution shall be reported with the spontaneousheating value so obtained.5. Significance and Use5.1 The spontaneous heating value of a substance is ameasure of the ability of that substance to undergo self-heatingreactions while supported by cellulosic or other fibrous mate-r
21、ial in air. It is an index of the autoignition tendency of thesubstance under such conditions.6. Apparatus6.1 Spontaneous Heating ApparatusSee Fig. 1 and Fig. 2.6.2 Thermocouples, 30-gage, iron-constantan, Type J. Twoare required.6.3 Strip Chart Temperature Recorder, two-channel or mul-tipoint, capa
22、ble of 0.5 K resolution at test temperature.6.4 Hot Plate, capable of uniformly heating entire bottomsurface of spontaneous heating apparatus.7. Materials7.1 Cotton Gauze, surgical.7.2 Water, conforming to Specification D 1193, Type III.8. Procedure8.1 Determination of Instrumental Blank:8.1.1 Assem
23、ble the spontaneous heating apparatus andplace 2000 mL of distilled water in the boiling chamber. Heatthe apparatus until continuous refluxing occurs.8.1.1.1 When test temperatures higher than that obtained bythe refluxing of water in the test apparatus are desired, reagentgrade ethylene glycol or a
24、ny other suitable pure compoundmay be substituted for water. Report any such substitutionswith the test data.8.1.2 Pack the sample and reference containers (screenbaskets) with 20 g of rolled cotton gauze. Insert a thermo-couple in the center of the gauze mass in each container andplace both in the
25、apparatus.NOTE 1When considerable variation in temperature from the normexists, an additional thermocouple may be necessary to measure thetemperature of the bath.8.1.3 Allow the system to attain thermal equilibrium andthen continue heating for 4 h. Record temperature readings, BRand BS. Determine th
26、e average instrumental blank TB, foundFIG. 1 Spontaneous Heating Apparatus (Copper Body)D 3523 92 (2007)2over the duration of the test from measurements of BSand BRmade at 1/2-h intervals after establishment of thermal equilib-rium.8.2 Measurement of Spontaneous Heating Value:8.2.1 Assemble the spon
27、taneous heating apparatus andplace 2000 mL of distilled water in the boiling chamber. Heatthe apparatus until continuous refluxing occurs.8.2.2 Pack the reference container (screen basket) with 20 gof freshly rolled cotton gauze.8.2.3 For a liquid sample, saturate 20 g of freshly rolledcotton gauze
28、with 10 g of liquid. For a solid sample record theparticle size if appropriate, and roll 10 g of a solid sample in 20g of fresh cotton gauze. Locate the sample as near as possibleto the position of the thermocouple tip. Pack the sample andgauze in the sample container (screen basket).NOTE 2For simul
29、ation of self heating of oily wastes and similarmaterials, it may be necessary to use the sample to gauze ratios as high as2:1.NOTE 3The SHV will tend to vary with the particle size of solidsamples.8.2.4 Samples that contain volatile components such assolvents in paint or coating materials may be co
30、nditioned toremove such solvents before being placed in the test apparatus.Conditioning will of necessity be determined by the nature ofthe sample and shall be described in the report.8.2.5 Insert thermocouples in the sample and referencecontainers.8.2.6 Allow the system to attain equilibrium (withi
31、n 1.5 K(1.5C) and then continue heating for 4 h. Record temperaturereadings, tRand tS.8.2.6.1 While the minimum duration shall be 4 h, extendedtest durations may be employed as required. The test durationshall be reported if a duration other than4hisemployed.9. Calculation and Report9.1 Tabulate the
32、 values obtained for tRand tSand thetemperature differences, Dt, which are associated with each asfollows:Dt 5 tS2 tR(1)9.2 Calculate the temperature difference found at the maxi-mum temperature, TS, attained by the sample as follows:DT 5 TS2 TR(2)9.3 Apply the instrument blank correction to the tem
33、pera-ture differences at Dt and DT as follows:DtC5Dt 2 BS2 BR! 5Dt 2DTB(3)DTC5DT 2 BS2 BR! 5DT 2D TB(4)9.4 Report the maximum value calculated for DtCor DTC(usually DTC) as the spontaneous heating value of the sample,SHV, at the initial reference temperature. For solid samples,report the particle si
34、ze.10. Precision and Bias10.1 Because of the complex nature of Test Method D 3523for spontaneous heating values, and because of the expensiveequipment involved, there is not a sufficient number ofvolunteers to permit a cooperative laboratory program forFIG. 2 Spontaneous Heating ApparatusD 3523 92 (
35、2007)3determining the precision and bias. If the necessary volunteerscan be obtained, a program will be undertaken at a later date.11. Keywords11.1 Differential Mackey Test; liquids; solids; spontaneousheating; spontaneous heating valuesASTM International takes no position respecting the validity of
36、 any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to
37、revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Y
38、our comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is co
39、pyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).D 3523 92 (2007)4
