空气比热容比之声速测量法

235Vol.23No.5201010PHYSICALEXPERIMENTOFCOLLEGEOct.2010:2010201219:100722934(2010)0520059203,,(,223001):;;FD2NCD:;;:O414.1:AFD2NCD,,,,,,,,,,1,,,dVV,dp,,dp,dp=KdVV(1),,K(1)(2)K=dpdVv(2),tx,v=Kp(3)1816,(P.S.M.deLaplase),,,pVpV=C(),pVr1+VdpdV=0p=dpdVV(4)(4)(2),K=p(5)(5)(3)v=p(6)p=1mRT(7)(6),(7)v=RTM=R(273.15+t)M(8)R=8.31J/(molK),t(),=cpcVM,,M=28.96103kg/mol(8),v,,=v2MRT=v2MR(273.15+t)(9)2,,100km,20.93%,78.07%,()0.94%,0.03%,0.03%,=53;,=1.40;,=43=530.94%+(20.93%+78.07%)1.40+0.06%43=1.40233.11,S1X(CH1),S2Y(CH2)13.1.1S1S2,40KHz(1)40KHz(2)Y(CH2),,,2(3),,,f2YS23.1.2(1)MODEDUAL,SOURCECH,S1,S2,3,3S1,S2(2),3,(3),S2,S1,S2S2,S2,S2,S2,S1,S2,S1,S2S2(4)S2,S1,S22,S2,S2(5)S2,10S23.2(1)t=9.5,f=39.68kHz(2)06li(mm)l1116.02l2107.586l399.072l490.555l582.044li+5(mm)l673.522l765.000l856.482l947.980l1039.470li=li+5li42.58042.58642.5942.57542.574l=15li=42.581mm=l5=8.516mm=8.516mm,v=f=39.688.516=337.915m/s,v(9)=v2MR(273.15+t)=1.408Er=100%=1.4021.4081.402100%=0.4%4FD2NCD4.1(1)FortonP0(2),P1(U1)T0()(3),P0(),(4)T0,P2(U2)(5)4,4.2PU:P1=P0+U1200104(Pa),P2=P0+U2200104(Pa),=1.357;:Er=1.4021.402100%=3.2%P0(Pa)U1(mv)U2(mv)P1(Pa)P2(Pa)=lgP1P0lgP1P21030601127.631.11094401046151.3322126.433.21093801047201.3673126.834.31094001047751.3824131.232.91096201047051.3455,FD2NCDFD2NCD,,S1,S2,S2,S1,S2,,():[1],.[M].:,2006.[2],.[M].:,1990.[3].[M].:,2003.ByusingtheSoundVelocityMeasureAirSpecificHeatRatioTANGYa2lu,HUGuang,ZHANGJun(HuaiyinInstituteofTechnology,Jiangsu,Huaian223001)Abstract:Thispaperpresentsthetheoreticalderivationoftheformulaspeedofsound;Proposedusingsoundvelocitytomeasureairspecificheatratio;TheerrorsofthesoundvelocitymeasurementmethodandoftheFD2NCDtypeair2specificheatratiodetectormeasurementmethodwerecompared.Keywords:speedofsoundformula;airspecificheatratio;phasecomparison16