Flow meter model RCD is used for measuring and monitoring liquid and gas fl ows. The device works on the well-known principle of the Venturi nozzle. A small pressure difference proportional to the fl ow is produced by the fl owing medium at an orifi ce constriction (nozzle) in the device hous-ing. The shape of the nozzle is based on the fl ow, where-by the fl ow characteristic remains constant over the entire measuring range. Drill holes are located in the housing fi tting to absorb the resulting differential pressure and transfer it to a differential-pressure measuring cell fi tted in the housing.
If the fl ow is exceeded the differential pressure measuring cell is protected by locking pins. On mechanical displays the fl ow rate measured by the pressure measuring cell is transferred via a pointer movement to the pointer indicator calibrated in L/min water or m3N/h air. On electronic displays the mechani-cal motion is converted to an electrical signal by a Hall-sen-sor. Various electronic modules are then used to display and monitor the volumetric flow.Special scales are available for all media at any pressure and any temperature.