For the dredging industry, it is very important to be able to accurately measure the density of the dredging slurry. Normally, the density is measured through the use of nuclear technology. However, environmental concerns mean that the use of nuclear solutions are becoming more problematic. Dredging companies are showing a willingness to switch to measurement technologies that rely on non-nuclear sources. It is now possible to measure density by means of ultrasonic technology. This density measurement is based on measuring the acoustic impendance of the slurry in question. The attenuation of the ultrasonic signal is measured, which is then translated into density. Typically, a 9690 model or SDM density meter is used for this application: an ultrasonic sensor is placed in line and a continuous density parameter is shown.