Abstract
In this paper, we present an ultrasonic transducer for the detection of hydrocarbon pollutants with a given concentration threshold. The device is made by screen-printing using piezoelectric PZT (Lead Zirconate Titanate). The piezo device is used as an ultrasound emitter and receiver that allow the measurement of sound velocity in a liquid medium, the value of the sound velocity being modified by the presence of pollutants.