How do you know the pump is really pumping? Designed for Holliston, Mass.-based Walchem Corp.’s EH and EZ Series pumps, the PosiFlowO Sensor detects the flow of liquid output by the pump, which verifies the metering pump is moving liquid and hasn’t lost prime. The PosiFlowO accomplishes this with no moving parts. The standard flow path of the pump is preserved so the liquid doesn’t go through gears or move a magnet to actuate a pulse in the sensor. This eliminates plugging or jamming concerns.