A capacitive pick off sensor for a mass flow measurement device is disclosed. The mass flow measurement device includes a flow sensor tube and a drive device for vibrating the flow sensor tube. The capacitive pick off sensor includes at least one conductive plate connectable to a first voltage potential and adapted to be situated adjacent the flow sensor tube which is connected to a second voltage potential. The conductive plate is positioned relative to the flow sensor tube so as to define a gap therebetween. The capacitance between the conductive plate and the flow sensor tube varies due to the relative motion of the conductive plate and the flow sensor tube when the flow sensor tube is vibrated. In other aspects of the present invention, the flow sensor tube is situated in a housing and the drive device is positioned outside the housing for vibrating the flow sensor tube.

Coriolis mass flow controller

A dynamometer provides an apparatus and method for testing a torque converter without requiring that an automotive transmission be attached. The dynamometer includes a prime mover mounted on a frame for driving the torque converter. A dynamic loading device with an eddy current brake is movably mounted on the frame. An adapter extends between the loading device and the torque converter and has passages for routing hydraulic fluid to and from the torque converter. Sensors connected to a computer monitor pressures, temperatures and fluid flow.

Torque converter dynamometer and method of using same

A method for operating a vibrating flow meter system is provided. The method includes the step of receiving a first sensor signal from a first vibrating flow meter. A second sensor signal is received from a second vibrating flow meter. A first flow rate is generated from the first sensor signal and a second flow rate is generated from the second sensor signal. The method further includes the step of determining a differential zero offset of the first vibrating flow meter based on the first and second flow rates.

Method and apparatus for determining and compensating for a change in a differential zero offset of a vibrating flow meter

Signal processing of Coriolis flowmeter output signals is improved by increasing the frequency separation between the flow tube drive frequency and unwanted lateral mode vibration frequencies. A cylindrical lateral mode stabilizer surrounds the flow tube near each flow tube end and is positioned between the flow tube and a surrounding balance bar. Axially lateral extensions on opposing circumferential sides of each lateral mode stabilizer element stiffen the flow tube ends for only lateral vibrations. This raises the lateral mode vibration frequency of the flow tube while leaving the drive mode frequency relatively unaffected.

Lateral mode stabilizer for coriolis flowmeter

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 plurality of mode selective filtered motion signals and the first and second reference signals. According to other embodiments, a plurality of time difference estimates is generated from the plurality of phase estimates. According to still other embodiments, 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 structure under a known perturbation is estimated, and a system status is determined from the intercept parameter. The invention may be embodied as methods, apparatus and computer program products.

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

A mass flow meter provides improved accuracy in measuring the mass flow rate of a fluid flowing through a straight measuring tube. The as measured mass flow rate value is changed by parameters such as the Young's modules, second moment of area, length, axial force, etc. of the measuring tube. The parameters change with the strain caused in the axial direction of the measuring tube. A strain sensor is installed on a measuring tube, and the as measured mass flow rate is corrected based on the output of the strain sensor. Since the strain affects in a different way the substantial mass flow rate and the zero point offset, the correction is conducted separately on the substantial mass flow rate and on the zero point offset so that the accuracy of measurement may be improved. Since the parameters change also with the temperature of the measuring tube, a temperature sensor is also installed on the measuring tube so that the accuracy of measurement may be further improved.

Mass flow meter

The mass flow meter is based on the reaction force working according to Coriolis principle which is produced by acceleration of fluid flowing through straight measuring tube, and has a sensor system (10) for determining the voltage, which is caused axially in the measuring tube (2). A correction unit (9) corrects the measured value of the mass flow rate, on the basis of the output signal of the sensor system. The correction unit includes a mass flow rate correction unit for the correction of one part of the measured value, which corresponds to the actual flow rate of the fluid. A zero point correction unit is also provided, for correcting another part of the measured value, which corresponds to the zero point shift, which remains if the fluid is not flowing.

Keita Ohkawa

Papers

Mass flow meter

Mass flow meter for measuring mass flow rate of fluid