Model DR05 paddle-wheel flow sensors

Model DR05 paddle-wheel flow sensors are available to measure the flow of liquids with low viscosity similar to water. The flow sensor consists of a section of polypropylene pipe fitted with a paddle wheel that extends into the flowing liquid. The rotary motion of the plastic paddle wheel is detected by a Hall sensor, which provides output as a series of pulses whose frequency is directly proportional to the flowrate. Alternatively, the pulsed output can be converted into a 4-20-mA signal. Wetted materials include a polypropylene (PP) housing, ethylene chlorotrifluoroethylene (ECTFE) rotor, and ceramic axles and bearings. Viton seals are standard, with ethylene propylene diene monomer (EPDM) optional. The devices are available for pipe sizes of 1in. to 2 in. with turndown ratios of up to 50:1.