Micromotion Gmbh

David Lee Campbell

Timothy J Cunningham

Thomas Dean Sharp

Daniel Patrick McNulty

John Richard McCarthy

Kurtis Leroy McCormick

Movement of a structure, such a conduit of a Coriolis mass flowmeter, is estimated. A plurality of motion signals representing motion of the structure are mode selective filtered to generate a plurality of mode selective filtered motion signals such that the mode selective filtered motion signals preferentially represent motion associated with a vibrational mode of the structure. A plurality of phase estimates is generated from the plurality of mode selective filtered motion signals. The plurality of phase estimates may be generated using a phase reference derived from a mode selective filtered motion signal of the plurality of mode selective filtered motion signals. According to some embodiments, a frequency of a mode selective filtered motion signal is estimated, and quadrature first and second reference signals are generated based on the estimated frequency. The plurality of phase estimates is generated from the mode selective filtered motion signals and the reference signals.

Methods, apparatus, and computer program products for determining structural motion using mode selective filtering

Motion signals representing motion of a conduit of a mass flowmeter are mode selective filtered to generate a plurality of mode selective filtered motion signals such that the plurality of mode selective filtered motion signals preferentially represent motion associated with a vibrational mode of the conduit. A plurality of time difference estimates is generated from the plurality of mode selective filtered motion signals. A correlation measure is generated from the plurality of time difference estimates. A status of the mass flowmeter system is determined from the generated correlation measure. In some embodiments, the correlation measure comprises an intercept parameter of a scaling function that relates the plurality of time difference estimates to a plurality of reference time differences representing motion of the conduit at a known mass flow. In other embodiments, the correlation measure comprises a correlation coefficient estimated from the plurality of time difference estimates. In still other embodiments, the correlation measure comprises an error of estimate. The mass flowmeter system status may be determined by determining a change in the correlation measure, and corrective action may then be taken if the determined change satisfies a predetermined criterion. The invention may be embodied as methods, apparatus and computer program products.

Mass flowmeter methods, apparatus, and computer program products using correlation-measure-based status determination

Mass flow of a material in a conduit is estimated by mode selective filtering a plurality of motion signals representing motion of the conduit to generate a plurality of mode selective filtered motion signals such that the mode selective filtered motion signals preferentially represent motion associated with a vibrational mode of the conduit. A plurality of phase estimates is generated from the plurality of mode selective filtered motion signals. A mass flow estimate is generated from the plurality of phase estimates. The plurality of phase estimates may be estimated using a phase reference derived from one of the plurality of mode selective filtered motion signals. In some embodiments, a frequency of a mode selective filtered motion signal of the plurality of mode selective filtered motion signals is estimated. Quadrature first and second reference signals are generated based on the estimated frequency. The plurality of phase estimates is generated from the plurality of mode selective filtered motion signals and the first and second reference signals. A plurality of time difference estimates may be generated from the plurality of phase estimates, and the mass flow estimate may be generated from the plurality of time difference estimates. The plurality of time difference estimates may be generated from the plurality of phase estimates by dividing the plurality of phase estimates using a mode frequency estimated from the mode selective filtered motion signals. The invention may be embodied as methods, apparatus and computer program products.

Mass flow measurement methods, apparatus, and computer program products using mode selective filtering

A drive system for use in a temperature environment. The drive system is made of materials that can withstand high temperatures without degrading. There are no plastics or epoxy adhesives used in this drive system. The drive system is also made more efficient by placing the drive system on a flow tube outside of a loop in the flow tube between the inlet and the outlet.

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Boulder, CO, United States of America

David Lee Campbell