The E+H Proline Prosonic Flow P 500 Clamp-On Ultrasonic Flow Meter applies a non-invasive measuring principle independent of pressure, density, and conductivity. The meter provides a bidirectional measurement of various fluids, e.g. liquid hydrocarbons and chemicals. The built-in FlowDC (Flow Disturbance Compensation) maintains accuracy even when the meter is mounted with a short inlet run. A stable signal is accomplished via maintenance-free permanent mounting from outside with coupling pads. Sensors for GRP and plastic pipes are available. The freely combinable I/Os offer full access to process and diagnostic information, as well as variety and reduced complexity .

The measuring system uses a measurement method based on the transit time difference. In this measurement method, acoustic signals (ultrasonic) are transmitted between two sensors. Signal transmission is bidirectional, i.e. the sensor operates as both a sound transmitter and a sound receiver. As the speed of propagation of the sound waves is slower against the flow direction than in the flow direction, this results in a transit time difference. This transit time difference is directly proportional to the flow velocity. The measuring system calculates the volume flow of the medium from the measured transit time difference and the pipe cross-sectional area. The sound velocity of the medium is simultaneously measured along with the transit time difference. With this additional measured variable, it is possible to differentiate between different media or monitor the medium quality .

Only 2 x DN inlet and outlet runs are required when using 2 sensor sets and FlowDC. The measuring range is 0 to 50ft/s (0 to 15m/s) with nominal diameters from 1/2 to 160in. Medium temperature range is -40 to 302°F for DN15-65 and -40 to 338°F for DN50-4000. Maximum measurement error for volume flow is ±3% o.r. for DN15, ±2% o.r. for DN25 to DN200, and ±2% o.r. above DN200. The backlit display with touch control and WLAN access allows easy configuration. Standard cable between sensor and transmitter ensures reliable communication. The meter is designed for SIL applications .