Digital signal processing method of Coriolis mass flowmeter

For the contribution of negative frequency is neglected in the algorithm. there is a long convergence stage of using the sliding Goertzel algorithm to measure the phase difference between signals of Coriolis mass flowmeter. A new signal processing method for Coriolis mass flowmeter is proposed based on the recursive DTFT algorithm with the contribution of negative frequency considered. First, an adaptive lattice notch filter is applied to filter the sensor Output signals of Coriolis mass flowmeter and calculate the frequency. Then a method with negative frequency contribution based on the recursive DTFT algorithm is introduced to calculate the real-time phase difference between two enhanced signals. With the frequency and the phase difference obtained. the time interval of two signals is calculated and then the mass flow rate is derived. Simulation results show that the stage of convergence of phase difference and time interval calculation has been largely shortened by the new method. So the method is proved to be effective.