Frequency-Variance Based Antistrong Vibration Interference Method for Vortex Flow Sensor

Vortex flowmeter is apt to be disturbed by pipe vibration in industrial applications. It is a very difficult problem to be solved, and affects the applications of vortex flowmeter. To solve this key problem, the frequency features of the flow signal and vibration noise are analyzed. A frequency-variance algorithm is proposed to deal with the vortex flow sensor output signal. A variance threshold is set to distinguish the vortex flow signal from the vibration noise interference. A signal processing system based on an ultralow-power microcontroller is developed to implement the algorithm and to extract the flow rate information from the signal containing strong vibration noise. At the same time, this system meets the requirements of low-power and two-wire mode, and can be used in process control. The strong vibration experiments are conducted to validate the effectiveness of both antistrong vibration algorithm and the system. Only one vortex flow sensor is required in the vortex flowmeter, which avoids the design and installation of the vibration sensor and saves the costs of meter.