1、Designation: D3523 92 (Reapproved 2012)Standard Test Method forSpontaneous Heating Values of Liquids and Solids(Differential Mackey Test)1This standard is issued under the fixed designation D3523; the number immediately following the designation indicates the year oforiginal adoption or, in the case
2、 of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the non-adiabatic determinationof the spontaneous heating values (SH
3、V) 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 ofthe sample to air at the test
4、 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 determined by the presenttest method ar
5、e 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 obtained by the use of anadiabati
6、c 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 indication of the enthalpy and rate of
7、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 significance to the test results. It is s
8、ufficient, 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 temperature. A negative result does
9、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 todescribe or appraise the fire
10、-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 assessment of the firehazard or fire
11、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 concerns, if any, associated wi
12、th 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:2D1193 Specification for Reagent Water3. Terminology3.1 Definitions
13、 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 any time during test, K,tR= temper
14、ature of reference side at time tSis measured,K,1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility ofSubcommittee D02.L0.07 on Engineering Sciences of High Performance Fluids andSolids (Formally D02.11
15、00).Current edition approved April 15, 2012. Published April 2012. Originallyapproved in 1976. Last previous edition approved in 2007 as D352392(2007).DOI: 10.1520/D3523-92R12.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. Fo
16、r Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesNOTICE: This standard has either been superseded and replaced by a new v
17、ersion or withdrawn.Contact ASTM International (www.astm.org) for the latest information1TS= maximum temperature of sample chamber duringtest, K,TR= temperature of reference chamber measured at sametime that TSis measured, K,t = tS tR,T = TS TR,BR= equilibrium temperature of reference side duringbla
18、nk run, K,BS= equilibrium temperature of sample side during blankrun, K,TB= BS BR= instrumental blank,tC= t (BSBR)=t TB, andTC= T ( BS BR)=T TB= spontaneous heatingvalue.4. Summary of Test Method4.1 The sample is supported on surgical gauze and placed ina heated chamber which is open to the air at t
19、he 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 temperature of thesample exceeds that of the reference is taken as an index of thespontaneous heating value of the sample
20、. 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 as required.Any such substitution shall be reported with the spontaneousheating value so obtained.5. Significance and Use
21、5.1 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-rial in air. It is an index of the autoignition tendency of thesubstance under such conditions.6. Apparatus6.1 Spontaneou
22、s 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 ormultipoint, capable of 0.5 K resolution at test temperature.6.4 Hot Plate, capable of uniformly heating entire bottomsurface of spontaneou
23、s heating apparatus.7. Materials7.1 Cotton Gauze, surgical.7.2 Water, conforming to Specification D1193, Type III.8. Procedure8.1 Determination of Instrumental Blank:8.1.1 Assemble the spontaneous heating apparatus andplace 2000 mL of distilled water in the boiling chamber. Heatthe apparatus until c
24、ontinuous 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 any other suitable pure compoundmay be substituted for water. Report any such substitutionswith the test data.8.1.2 Pack the
25、 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 apparatus.NOTE 1When considerable variation in temperature from the normexists, an additional thermocouple may be necessary
26、 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, BRFIG. 1 Spontaneous Heating Apparatus (Copper Body)D3523 92 (2012)2and BS. Determine the average instrumental blank TB, foundover the duration o
27、f the test from measurements of BSand BRmade at12-h intervals after establishment of thermal equilib-rium.8.2 Measurement of Spontaneous Heating Value:8.2.1 Assemble the spontaneous heating apparatus andplace 2000 mL of distilled water in the boiling chamber. Heatthe apparatus until continuous reflu
28、xing 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 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 fres
29、h 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 simulation of self heating of oily wastes and similarmaterials, it may be necessary to use the sample to gauze ratios as high as2:1
30、.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 conditioned toremove such solvents before being placed in the test apparatus.Conditioning will of necessity be determined by the
31、 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 (within 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
32、 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 values obtained for tRand tSand thetemperature differences, t, which are associated with each asfollows:t 5 tS2 tR(1)9.2 Calc
33、ulate the temperature difference found at the maxi-mum temperature, TS, attained by the sample as follows:T 5 TS2 TR(2)9.3 Apply the instrument blank correction to the tempera-ture differences at t and T as follows:tC5 t 2 BS2 BR! 5 t 2 TB(3)TC5 T 2 BS2 BR! 5 T 2 TB(4)9.4 Report the maximum value ca
34、lculated for tCor TC(usually TC) as the spontaneous heating value of the sample,SHV, at the initial reference temperature. For solid samples,report the particle size.10. Precision and Bias10.1 Because of the complex nature of Test Method D3523for spontaneous heating values, and because of the expens
35、iveequipment involved, there is not a sufficient number ofvolunteers to permit a cooperative laboratory program fordetermining the precision and bias. If the necessary volunteerscan be obtained, a program will be undertaken at a later date.FIG. 2 Spontaneous Heating ApparatusD3523 92 (2012)311. Keyw
36、ords11.1 Differential Mackey Test; liquids; solids; spontaneousheating; spontaneous heating valuesASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determ
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40、ingle 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). Permission rights to photocopy the standard may also be secured from the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ 92 (2012)4
