阻抗管中的隔声量测试方法

:1006-1355(2006)04-0108-03袁健,贺才春,林胜(株洲时代新材料科技股份有限公司,湖南株洲412007):,,:;;;:TU112.2+1:AAMethodforDeterminingAcousticsTransmissionLossinImpedanceTubesYUANJian,HECai-chun,LINSheng(ZhuzhouTimesNewMaterialTechnologyCo.,Ltd,ZhuzhouHunan412007,China)Abstract:Introducestheprincipleofdeterminationofacousticstransmissionlosscoefficientofma-terialsbyfour-microphonemethod.Thetestmethodusingfourmicrophonetodeterminethetransmis-sionlossisparticularpresented.Thepresentmethodusestwomeasurementswithtwodifferentbound-aryconditionstocompensatefornon-idealanechoictermination.Theresultsturnoutthatthemeasure-mentisaccurate.Keywords:acoustics;transmissionloss;four-microphonemethod;impedancetube1:2005-09-07:(1977-),,,,,,()(),,,,,,,,10m2[1]5,1,,,,1dB,0.99[2][3],,12,(),P(x),=Ae-jkx+Bejkx,x[0(1)AB,2006842P(x)=Ce-jkx+Dejkx,x\d(2)CD,d,ABCDABCD,AB=t11t12t21t22CD(3),|A||C|,,D=0,,(3)t11TL=20log|A||C|D=0=20log|t11|(4)()ab,(3)AaBa=t11t12t21t22CaDa(5)AbBb=t11t12t21t22CbDb(6),a(5),b(6),(5)(6)t11=AaDb-AbDaCaDb-CbDa(7),,(7)CaCb,t11=Tin,aRb-Tin,bRaRb-RaRSD/C(x=0),,TinSA/C,(,),(7),(1)(2)P1=Ae-jkx1+Bejkx1P2=Ae-jkx2+Bejkx2P3=Ce-jkx3+Dejkx3P4=Ce-jkx4+Dejkx4(8)(8)A=j2P1ejkx2-P2ejkx1sin(k(x1-x2))B=j2P2e-jkx1-P1e-jkx2sin(k(x1-x2))C=j2P3ejkx4-P4ejkx3sin(k(x3-x4))D=j2P4e-jkx3-P3e-jkx4sin(k(x3-x4))(9),O,O(9)O*A=j2GO1ejkx2-GO2ejkx1sin(k(x1-x2))O*B=j2GO2e-jkx1-GO1e-jkx2sin(k(x1-x2))O*C=j2GO3ejkx4-GO4ejkx3sin(k(x3-x4))O*D=j2GO4e-jkx3-GO3e-jkx4sin(k(x3-x4))(10),GO1,GO2,GO3GO41,2,34,1,GO1(8)(9)(10)abO*aO*b(7)t11=(O*aAa)(O*bDb)-(O*bAb)(O*aDa)(O*aCa)(O*bDb)-(O*bCb)(O*aDa)(11),ab(10)2B&K1094206T,3100mm,1150mm,50Hz~1.6kHz20mm,434,2mm,,100mm,,:,/0,,/0,,5/0,1dB,6,/0,/0,,7B&K7758,50Hz~1.6kHz,1810dB~21dB,/0,5/06/07/081(Hz)50100200300400500600(dB)21.119.818.316.515.113.612.2(Hz)7008009001000120014001600(dB)10.810.511.312.314.115.316.2(116)20068489:,,,,,:[1],.[J].,2004;23(6):637-639.[2],.[M].:.2001.[3]C.F.,,.[M].:.1988.(110)3(1),,,;(2),,;(3),,,,,,:[1],.[M].:,2004,7.[2],.[J].,2000(6):41-43.[3],.[J].,2002(6):44-46.(113),,(0.3~1.0)D2,;90b;2),,,FFT,10s3),,,,200Hz;,1000Hz4),,,,,,:[1].[J].,1992(10):34-41.[2]21IAHR(C)9-12.[3].[J].,2003(4):27-30.[4],,.CFD[J].,2004(7):21-23.[5].[J].,2005(3):56-58.200684