Surface analysis.


Surface analysis

The surface of an object is almost always easy to check. It helps to understand if one images the ultrasonic as light and the object as a polished mirror. If light hits the mirror, it is completely reflected (angle of incidence equals angle of reflection). If the mirror is not polished but dusty or dirty or has a crack the light is partially scattered to other directions. The resulting loss in the intensity of the reflected light can be measured e.g. with a photo diode. The ultrasound Receiver can analogously measure the loss in the intensity of the reflected ultrasonic waves.

The figures 1 and 2 show two different surfaces of Styrodur (an insulating material). The surface has to be rough, but neither too rough nor too smooth.


Figure 1


Figure 2