1、Designation:D276695(Reapproved 2009)Standard Test Method forSpecific Heat of Liquids and Solids1This standard is issued under the fixed designation D2766;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A num
2、ber 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 Department of Defense.1.Scope1.1 This test method covers the determination of the heatcapacity
3、 of liquids and solids.It is applicable to liquids andsolids that are chemically compatible with stainless steel,thathave a vapor pressure less than 13.3 kPa(100 torr),and that donot undergo phase transformation throughout the range of testtemperatures.The specific heat of materials with higher vapo
4、rpressures can be determined if their vapor pressures are knownthroughout the range of test temperatures.1.2 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.1.3 This standard does not purport to address all of thesafety concerns
5、,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:2D1217 Test Method for Density and Relative Dens
6、ity(Spe-cific Gravity)of Liquids by Bingham Pycnometer3.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 specific heatthe ratio of the amount of heat neededto raise the temperature of a mass of the substance by aspecified amount to that required to raise the temperature of anequal
7、 mass of water by the same amount,assuming no phasechange in either case.3.2 Symbols:Tf=temperature of hot zone,C,Tc=initial temperature of calorimeter,C,T8=Tf Tc=temperature differential,C,R1=resistance of nominal 1-V standard resistor,R100=resistance of nominal 100-V standard resistor,R10 000=resi
8、stance of nominal 10 000-V standard resistor,E1=emf across nominal 1-V standard resistor,E100=emf across nominal 100-V standard resistor,E10 000=emf across nominal 10 000-V standard resistor,tc=time of application of calibration heater current,s,q=total heat developed by calibration heater,cal,DEc=t
9、otal heat effect for container,mV,DEs=total heat effect for sample+container,mV,Dec=total heat effect for calibration of calorimetersystem during container run,mV,Des=total heat effect for calibration of calorimetersystem during sample run,mV,DHc=total enthalpy change for container changing fromTfto
10、 Tc,DHT=total enthalpy change for sample plus containerchanging from Tfto Tc,DHs=total enthalpy change for sample changing from Tfto Tc,F=calorimeter factor,W=weight of sample corrected for air buoyancydf=density of sample at Tf,dc=density of sample at Tc,VT=total volume of sample container,Vf=volum
11、e of sample vapor at Tf,Vc=volume of sample vapor at Tc,Pf=vapor pressure of sample at Tf,Pc=vapor pressure of sample at Tc,Nf=moles sample vapor at Tf,Nc=moles sample vapor at Tc,N=moles sample vapor condensed,DHv=heat of vaporization of sample,R=gas constant,andK=heat of vaporization correction.3.
12、3 Units:3.3.1 The energy and thermal(heat)capacity units used inthis method are defined as follows:1 cal(International Table)=4.1868 J1 Btu(British thermal unit,International Table)=1055.06 J1This test method is under jurisdiction of ASTM Committee D02 on PetroleumProducts and Lubricants and is the
13、direct responsibility of Subcommittee D02.L0.07on Engineering Sciences of High Performance Fluids and Solids(FormallyD02.1100).Current edition approved Oct.1,2009.Published November 2009.Originallyapproved in 1968.Last previous edition approved in 2005 as D276695(2005).DOI:10.1520/D2766-95R09.2For r
14、eferenced ASTM standards,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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Cons
15、hohocken,PA 19428-2959.United States1 1 Btu/lb F=1 cal/g C1 Btu/lb F=4.1868 J/g K3.3.2 For all but the most precise measurements made withthis method the rounded-off value of 4.19 J/cal can be used asthis is adequate for the precision of the test and avoids thedifficulty caused by the dual definitio
16、n of the calorie.4.Summary of Test Method4.1 The enthalpy change,DHc,that occurs when an emptysample container is transferred from a hot zone of constanttemperature to an adiabatic calorimeter at a fixed initialtemperature is measured for selected hot zone temperaturesevenly spread over the temperature range of interest.4.2 The enthalpy change,DHT,that occurs when a containerfilled with the test specimen is transferred from a hot zone ofconstant temperature,Tc,to an adiabatic calorimeter at a fi
