In 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. It’s very important for there to be an absolutely reliable and accurate measurement even at low liquid levels, right down to the vessel bottom.