Measure low flow rates in almost any size pipe. These sensors contain an open-core rotor with a small magnet in each of the four blades. As they rotate, the magnets pass a Hall effect sensor, which generates a linear frequency output that is proportional to the flow velocity. This signal travels up to 1000 feet without amplification. The open-core design eliminates cavitation at flow velocities from 0.3 to 20 ft/second. Closed or solid paddle-wheel designs create air bubbles at these velocities, causing a nonlinear and non-repeatable signal. Sensor materials resist most chemicals. All models have PVDF rotor and Viton O-ring; and include a 25-ft connecting cable. ROTOR-X low-flow sensors are compatible with all of our line-powered flow indicators, accumulators, and controllers. Mount in any type of pipe. Order installation fittings separately. Measure low flow rates down to 0.3 ft/second.