초록 ▼

Displacement sensors at opposite ends of at least one oscillating conduit produce output signals from which the drive component or the Coriolis component, or preferably both, are recovered. An oscillatory drive signal is derived from the drive component, and a mass flow signal is derived from the Co

Displacement sensors at opposite ends of at least one oscillating conduit produce output signals from which the drive component or the Coriolis component, or preferably both, are recovered. An oscillatory drive signal is derived from the drive component, and a mass flow signal is derived from the Coriolis component. The remaining drive component in a combination of the two sensor outputs is nulled by amplitude control of one sensor output. Two force drivers at opposite ends of the conduit are driven by complementary drive signals to which a perturbation signal is added. The remaining perturbation signal in a combination of the two sensor outputs is nulled by adding compensation to both drive signals to eliminate drive force imbalance. Synchronous demodulation is used in the preferred embodiment to detect several parameters in a combination of the sensor outputs. In a dual loop configuration, pairs of sensors and/or force drivers are located at opposite ends of each conduit section.

대표청구항 ▼

A signal processing and control method for a Coriolis mass flowmeter having several oscillating conduit sections, comprising oscillating a conduit section having two ends such that it undergoes angular motion about a substantially fixed intermediate point along the length of said section, for each e

A signal processing and control method for a Coriolis mass flowmeter having several oscillating conduit sections, comprising oscillating a conduit section having two ends such that it undergoes angular motion about a substantially fixed intermediate point along the length of said section, for each end of said section detecting a parameter which is a function of the displacement of the respective end of said section and producing two corresponding complementary sensor outputs, each including a drive component and a Coriolis component, oscillating at least one other conduit section having two ends in synchronism with said one section such that said other section undergoes angular motion about a substantially fixed intermediate point along the length of said other section, for each end of said other section detecting a parameter which is a function of displacement of the respective end of said other section and producing two other corresponding complementary sensor outputs, combining corresponding ones of the individual sensor outputs for the several conduit sections to form two combined sensor outputs, and recovering at least one of said components from said two combined sensor outputs.