Processing Magazine

Liquid vortex flow sensor features high accuracy and low cost

November 18, 2009
The sensors are designed specifically for system flow monitoring and control. Combining high accuracy and low cost, the flow sensors are accurate to 1 percent fs of measured value. The models are suitable for flow ranges from 0.9 to 150 liters per minute. The vortex flow sensors operate on the principle of Kármán’s vortex trail. The models utilize piezoelectric sensors embedded in an ETFE vane located downstream of the bluff to detect the generated vortices. The frequency measured represents the flow velocity. The result is a temperature insensitive measurement of flow with minimal pressure loss. A flow factor is provided to convert frequency to volume flow rate for each model size. Versions with a 1000 Ohm RTD temperature sensor built-in to the bluff are available, providing direct temperature measurement in the medium.