At a recycling company, oil sludge, oil/water mixtures and emulsions from many industrial processes are collected and treated. The objective is to separate the oil and water for recovery, purification and reuse. This process takes place in several steps. Firstly the oil/water mixture is centrifuged, hydrogen peroxide is added and mixed in a stirring reactor, then finally it is centrifuged again. Continuous level measurement is required in the reactor stage to enable automated operation. Its very Important for there to be an absolutely reliable and accurate measurement even at low liquid levels, right down to the vessel bottom. Inside the reactor there are baffles and an agitator. During the process sometimes heavy vapours are given off along with condensation, the liquid density also changes. Also note how close to the edge the mounting point is.