DEVELOPMENT OF A THERMOELECTRIC SENSOR FOR ULTRASONIC INTENSITY MEASUREMENT

The design of ultrasonic reactors lies partly upon the description of the ultrasonic intensity space and time distribution. Among other techniques the thermoelectric probe seems to be one of the most appropriate tools to measure the intensity available. It consists of a thermocouple embedded in an absorbing material (silicone). The modelling of the heat transfer allows the establishment of the relationship between the temperature signal response of the probe and the ultrasound intensity. It is shown that either the initial rate of temperature rise or the difference between the steady-state probe temperature and the medium temperature can be used, In addition, the measurements show the importance of the height and nature of the liquid sonicated on the ultrasonic intensity distribution.