PLL CONTROL OF THE CORIOLIS METER RESONANCE FREQUENCY

摘要

The Coriolis meter is used for direct measurements of fluid density and mass flowrate. Its regular operation is conditional on the vibration of its measuring tube at the resonance frequency. The accuracy and quickness of the resonance control have an impact on static and dynamic meter characteristics. In the paper, results of using a phase-locked loop (PLL) control system are presented. The measurements were performed on a straight-tube meter with an electromagnetic exciter and piezoelectric accelerometers.