A novel technique to measure the magnitude and direction of flow in a tube

This paper describes a novel in-line sensor that measures the magnitude and direction of gas flow in a tribe. The sensor possesses a unique set of per formance characteristics: low detection limit, little resistance to flow: a nd directional sensitivity. The sensor consists of two hot wire anemometers mounted in a U-shaped tube. Differences in the signals between the two hot wires under low velocity conditions are used to determine the direction of the pow. Calibration curves of flow rate versus measured velocity are used to determine the magnitude of the flow. The sensor has applications in sys tems that are characterized by naturally driven oscillating flows . [S0098- 2202(00)02701-2].