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[单选题]
用2.5MHz,Φ25mm直探头测定厚度100mm钢板的材质衰减,设钢板表面往返损失1dB,现在测得(B1£B2)=5dB,则双声程衰减系数为()
A.0.04dB/mm
B.0.020dB/mm
C.0.0625dB/mm
D.0.03125dB/mm
查看答案
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A.0.04dB/mm
B.0.020dB/mm
C.0.0625dB/mm
D.0.03125dB/mm
A.2.5MHz双晶直探头
B.4-5MHz双晶直探头
C.4-5MHz单晶直探头
D.5MHz单晶直探头
A.5MHz10x2,焦距30mm双晶直探头
B.2.5MHzΦ14mm直探头
C.2.5MHzΦ20mm直探头
D.2.5MHz8x10mm,60°斜探头