Analysis and Suppression of Mechanical Coupling Vibrations of Coriolis Mass Flowmeter

Coriolis mass flowmeter (CMF) measures the mass flow of fluid by taking advantage of the coriolis force effect resulted from the resonant vibration of measurement tubes. The mechanical coupling vibration of sensor is commonly seen during the actual working process of CMF, which has direct influences to the stability and the measuring accuracy of the flowmeter and to which, there are still no perfect theoretical guidance and technical solution available for the time being, Theoretical analysis has been made to the sensor regarding the factors such as the structural coupling of the measurement tubes as well as the flexural vibrations of the upper cover in combination with the coupling relations of the mechanical structure of the CMF sensor. Based on the analyzing results, the structure of the sensor is modified accordingly and a plan for reducing the vibration coupling of the CMF sensor with double or multiple distance plates is put forward. The comparative measurement has been made to the original and modified CMF sensor with laser vibrometer, which proved that the modified CMF sensor effectively suppresses the mechanical coupling vibrations. And the experiments conducted for measuring flow with static weighing method has shown a significantly improved measuring stability of the modified CMF sensor.