ASTM_D_4611_-_08.pdf

Designation:D461108Standard Test Method forSpecific Heat of Rock and Soil1This standard is issued under the fixed designation D4611;the number immediately following the designation indicates the year oforiginal adoption or,in the case 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 determination of instanta-neous and mean specific heat of rock and soil.1.2 This test method employs the classical method ofmixtures.This provides procedures and apparatus simpler thanthose generally used in scientific calorimetry,an accuracy thatis adequate for most rocks and soils,and a degree of precisionthat is reproducible by laboratory technicians of average skill.While this test method was developed for testing rock and soil,it is easily adaptable to measuring the specific heat of othermaterials.1.3 The testing procedure provides an instantaneous specificheat over the temperature 25 to 300C or a mean specific heatin that temperature range.1.4 The test procedure is limited to dry samples.1.5 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are mathematicalconversions to inch-pound units that are provided for informa-tion only and are not considered standard.1.6 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 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:2C303 Test Method for Dimensions and Density of Pre-formed Block and BoardType Thermal InsulationC351 Test Method for Mean Specific Heat of ThermalInsulation(Withdrawn 2008)3D618 Practice for Conditioning Plastics for TestingD2766 Test Method for Specific Heat of Liquids and SolidsE230 Specification and Temperature-Electromotive Force(EMF)Tables for Standardized ThermocouplesE344 Terminology Relating to Thermometry and Hydrom-etry3.Terminology3.1 Definitions:3.1.1 instantaneous specific heatthe rate of change ofsample enthalpy,h,per unit mass with respect to temperature,T,at constant pressure,p,cp5h/T!p(1)3.1.2 mean specific heatthe quantity of heat required tochange the temperature of a unit mass of a substance onedegree,measured as the average quantity over the temperaturerange specified.(It is distinguished from true specific heat bybeing an average rather than a point value.The unit ofmeasurement is joule per kilogram kelvin,J/kgK).3.1.3 thermal capacitythe amount of heat necessary tochange the temperature of the body one degree.For a homo-geneous body,it is the product of mass and specific heat.Fora nonhomogeneous body,it is the sum of the products of massand specific heat of the individual constituents.Thermalcapacity has the units of joule per kelvin,J/K.3.1.4 thermal diffusivitythe ratio of thermal conductivityof a substance to the product of its density and specific heat.Common unit for this property is m2/s.3.2 Symbols:3.2.1 Henthalpy change(J/kg).3.2.2 mcpthermal capacity(J/K).3.2.3 Tmfinal temperature of the mixture obtained byextrapolation(K).3.2.4 Tctemperature of the calorimeter immediately priorto drop obtained by extrapolation.3.2.5 Thtemperature of capsule and sample,capsule orstandard in the heater prior to drop(K).3.2.6 Ttemperature difference.3.2.7 c pmean specific heat(J/kgK).3.2.8 cpinstantaneous specific heat(J/kgK).1This test method is under the jurisdiction ofASTM Committee D18 on Soil andRock and is the direct responsibility of Subcommittee D18.12 on Rock Mechanics.Current edition approved July 1,2008.Published July 2008.Originally approvedin 1986.Last previous edition approved in 2004 as D4611 86(2004).DOI:10.1520/D4611-08.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandardsvolume information,refer to the standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 4.Summary of Test Method4.1 The method of mixtures consists essentially of adding aknown mass of material at a known temperature to a knownmass of calorimetric fluid at a known lower temperature anddetermining the equilibrium temperature that results.The heatabsorbed by the fluid and containing vessel can be calculatedfrom calibrations and this value equated to the expression forthe heat given up by the hot material.From this equation,theunknown specific heat can be calculated.If only one drop froma single temperature is performed,then only the mean specificheat can be calculated.If several drops are performed,theinstantaneous specific heat can be calculated.5.Signi