The experimental determination of characteristic parameters of soft coatings such as biofilms and protein deposits is essential for the study of biotechnological and chemical engineering problems. The technique of fluid dynamic gauging allows the thickness and strength of soft fouling layers to be measured in situ and in real-time under different flow conditions. It is possible to monitor the thickness and strength of biofilms and protein deposits. Different operating modes and nozzle designs allow deposit specific investigations. This paper reports some recent developments of the technique.