Green Robert E
Materials Science and Engineering Department, Johns Hopkins University, 102 Maryland Hall, 3400 N. Charles Street, Baltimore, MD 21218-2689, USA.
Ultrasonics. 2004 Apr;42(1-9):9-16. doi: 10.1016/j.ultras.2004.01.101.
Non-contact generation and detection of acoustic and ultrasound waveforms is of practical importance, since it permits making acoustic and ultrasonic measurements at elevated temperatures, in corrosive and other hostile environments, in geometrically difficult to reach locations, in outer space and doing this at relatively large distances from the test structure. Non-contact acoustical and ultrasonic techniques currently available are laser generation, optical interferometric detection, electromagnetic acoustic transducers (EMATs), air(gas)-coupled systems and hybrid combinations of the above. The present paper will describe how several such systems have been used in unique materials characterization applications.
非接触式产生和检测声波及超声波波形具有实际重要性，因为它允许在高温、腐蚀性及其他恶劣环境、几何形状难以触及的位置、外层空间进行声学和超声测量，并且能在距测试结构相对较远的距离进行测量。目前可用的非接触声学和超声技术有激光产生、光学干涉检测、电磁超声换能器（EMAT）、空气（气体）耦合系统以及上述方法的混合组合。本文将描述其中几种系统如何用于独特的材料表征应用。
