Authors: Hanspeter Loertscher, Bert Grandia, Jan Strycek, and Willem A. Grandia


1. Introduction

2. Air-coupled Transducers

Flat air-coupled transducer, backed by air and with a thin front layer with low impedance. Focusing air-coupled transducer with spherically shaped ceramic disk. Focusing air-coupled transducer with composite ceramic element. Focusing air-coupled transducer. Flat disk with refractive lens added. Focusing air-coupled transducer. Flat disk with reflecting optics added.

3. Airscan Apparatus and Technique

4. Applications

Air-coupled transducers can be configured to work in through-transmission, like water-coupled transducers. It is, however, a distinct feature of air-coupled transducers to be able to efficiently generate guided plate waves (Figure 3), which are otherwise rapidly dampened by the water couplant. fig3m.gif (4345 bytes)

5. Conclusions

6. References