The sensor-fitting Type S030 has a built-in paddle wheel to measure the flow rate and is especially designed for use with neutral, slightly aggressive, solid free liquids. The compact sensor-fitting (S030) must be equipped with a Bürkert transmitter (SE30, SE30 Ex, SE32, SE35, SE36 or 8611) quickly and easily connected together by a bayonet catch. The Bürkert “Inline quarter-turn” technology is a construction ensuring a leakage free operation. The paddle wheel rotation (permanent magnets included in the wheels) is detected contactless through the sensor-fitting wall. The transmitter can be snapped-on or removed without opening the pipe or interrupting the process.