Method of determining an interface height of an interface between an upper and a lower layer comprised in a thickener

A Method of determining an interface height (h) of an interface (1) between an upper layer (3) and a lower layer (5) comprised in a container (7) of a thickener (9), wherein said thickener (9) is designed to perform a thickening process, wherein particles suspended in a medium supplied to the container (7) are separated from a liquid comprised in the medium, and wherein said upper layer (3) comprises said liquid floating on said lower layer (5) comprising said particles, is described, which improves the availability of the determination of the interface height. This method comprises the method steps of: measuring said interface height (h) with an interface level measurement device (L) installed on said thickener (9) during time periods, when conditions prevailing at said thickener (9) permit performance of these measurements, with a group of measurement devices installed on said thickener (9) measuring process variables (v