| 摘要 |
<p>A method and apparatus are disclosed for detecting a surface feature of a metallic object of interest or determining dimensional information regarding an object of interest based on the product of transmitted and reflected signals. In one embodiment, a detector (10) for detecting cracks (18) in a surface (16) is provided. The detector (10) comprises a signal generator (12); a waveguide (14) for receiving a first signal from the generator (12) and a second signal reflected off the surface (16), wherein the first and second signals interact to form a standing wave within the waveguide (14); and a sensor (24) for measuring the standing wave. By monitoring output from the sensor (24) as the waveguide (14) is scanned across the crack (18), the crack (18) can be detected. The detector (10) can also be used for measuring the dimensions of cracks.</p> |
