For potentially explosive areas and media, Katronic has developed an ATEX-certified system that also enables flow measurement in Ex zones 1 and 2. A key feature of Katflow 170 is the pressure-encapsulated housing made of epoxy-coated aluminum, which safely contains any sparks that may occur. The corrosion-resistant material also withstands difficult environmental conditions in the long term. The encapsulation does not need to be opened for command input either; control is by means of magnet-sensitive buttons behind glass, which are operated with a corresponding magnetic pen. In addition, encapsulated transducer pairs with IP68 protection are used for the sensors. The two ultrasonic sensors required for measurement are clamped to the pipe in question from the outside and are ready for use within a few minutes. The ultrasonic transducers send and receive signals both in and against the direction of flow, whereby the flow movement between the two directions results in a time difference in the transmission. The system determines the flow velocity from this difference in transit time and calculates the flow volume with reference to the outer diameter and wall thickness of the pipe. The resolution is 0.25 mm/s, the measuring accuracy of the flow velocity is up to ±0.5 % of the measured value. The device is suitable for pipe diameters from 10 mm to 3000 mm and temperatures from -50 to +115 °C.