Ultrasonic density measurement of polymer melts in extreme conditions

In-line real time monitoring and measurement of density of manufactured products is very important in various industrial applications, especially during extrusion of polymer melts. In this case measurements must be performed in very complex conditions, for example at high temperature (up to 400°C), high pressure (up to 10 MPa) and high chemical activity of the medium, mechanical impacts. Such extreme conditions limit the number of measurement techniques which can be used. The objective of this work was to develop and investigate an in line ultrasonic density measurement technique of polymer melts.