GUIDED ELASTIC WAVE SENSORS

The sensors described here have been studied in our laboratory. The industrial development of some of them is now in progress. They exploit the properties of elastic waves propagating, according to a chosen mode, in a plate or in a cylinder. The sensors comprising a plate are a graphic tablet, a map coordinate resolver, a touch screen and a liquid presence detector. The sensors comprising a cylinder are a liquid presence detector and a liquid level sensor. Before describing these devices, we comment on the dispersion curves and express the attenuation factor for guided waves in presence of a liquid.