超声波特性实验

×20-120-11/420-220-3θθ=01234567820-2ab20-3irIZZZZI21212)(+−=IiIrZ1Z2Z=ρC,ρCBαvSSLL11sinsinsinvvvααα==20-1SSLL22sinsinsinvvvββα==20-2αLαSβLβSv1Lv1S1v2Lv2S220-4vvSvSvLα)(sin11Lvv−=αα)(sin12Svv−=αα1-α220-720-4JDUT-2(1)400VCH1CH2TRG20-5(20-6)20-520-620-61120-71290dB2V20-72370-80dBR1R2AB220-8120-812t1t2∆tt1t1=t+∆t,t2=2t+∆t.∆t20-3212ttt−=∆40mm220-63R1R2B1B2t1t2R1=2R220-332)(0ttL−=v20-4vt0t12)(12ttL−=v20-5t11t221()()20-62R2R220-9B1B220-3020-63R1R220-1020-9420-10xt2cm6320-4xt02xtCx−=20-6C20°C1483m/s1t2x20-120-220-3m/s/DIV/sL/mR26.27×103m/s3.10×103m/s2.90×103m/s20-4x/mt1/st2/st3/st/s0.1000.1200.1400.1600.1800.20040mm14t12345-2.73×103m/s