Many industrial processes involve two separate phases. The fast reaction time of the sensor and electronics provide a quick response for detecting the phase change. This is possible in continuous as well as in batch processes.

The increasing degree of automation requires reliable sensor solutions for certain detection of these phase interfaces in the running process. The application of sound velocity technology yields the following advantages:

• Displacement of manual detection principals (e.g. visual), thereby elimination of human factors to achieve a higher level of safety
• Redemption of inaccurate non-direct methods (e.g. time operation) to achieve a higher level of productivity

In a continuous batch process, the response signal of the sound velocity can be used for the direct control of a multi way valve. This allows a separation between the product, intermediate and carrier phase.

The sensor response time is typically less than one second.

Two sensors, installed at different heights of a settling tank control the separation of the process stream into the product phase and the carrier phase. In this application, the sound velocity value of each phase will be kept constant, while switching the valves of every outlet.

A typical application is the separation of process waste water into a stream, into the effluent treatment and into the recovery stream.