Abstract: A noise reduction system and method for measuring the phase difference between output signals of a Coriolis flowmeter. The output signals are applied to signal processing circuitry having three measurement channels, each of which includes a multi-pole filter having a relatively large phase shift. A channel pair is alternately switched in successive time intervals between a calibration status and an active status. In the calibration status, the two channels are connected during one time intervals to the same input signal and the output signals of the two channels are measured to determine the inherent phase delay between the two calibration channels. The two channels are then switched during the next time interval to an active status in which they are connected separately to the two output signals from the flowmeter.

Abstract: A Coriolis mass flow rate meter for measuring the mass flow rate of material flowing through a conduit. The flow meter includes at least one flow tube through which the material to be measured passes. The flow tube is vibrated at its natural frequency so that the concurrent flow of material through the vibrating tube produces a displacement of the tube with the magnitude of the displacement being dependent upon the magnitude of the generated Coriolis forces and the mass flow rate of the measured material. The phase of the displacement of the flow tube is measured using optical fiber sensors comprising at least one loop of optical fiber which is flexed by the displacement of the flow tube. This flexing of the fiber causes a corresponding change in its optical conductivity and a corresponding change in the intensity of the light transmitted through the fiber from a light signal source to a signal detector.

Abstract: A Coriolis mass flow rate meter for measuring the mass flow rate of material flowing through a conduit. The flow meter includes at least one flow tube through which the material to be measured passes. The flow tube is vibrated at its natural frequency so that the concurrent flow of material through the vibrating tube produces a displacement of the tube with the magnitude of the displacement being dependent upon the magnitude of the generated Coriolis forces and the mass flow rate of the measured material. The phase of the displacement of the flow tube is measured using optical fiber sensors comprising at least one loop of optical fiber which is flexed by the displacement of the flow tube. This flexing of the fiber causes a corresponding change in its optical conductivity and a corresponding change in the intensity of the light transmitted through the fiber from a light signal source to a signal detector.

Abstract: A viscometer for improved sanitary measurement of the viscosity of industrial fluids. The present invention provides a viscometer integral with a flow meter or a viscometer than can be mounted onto an existing flow meter. The viscometer includes two adjacent parallel flow channels having relatively flat inner surfaces. A differential pressure element is mounted between the adjacent flow channels to sense the differential pressure between the fluid flow of the two channels. The differential pressure is input along with the mass flow rate and fluid density to calculate the fluid viscosity.

Abstract: A Coriolis flowmeter having a pair of parallel vibrating flow tubes equipped with a driver and sensors each comprising a fixed non-movable coil and a pair of magnets affixed to the vibrating flow tubes. Each coil magnetically cooperates with a unique pair of magnets. In a first embodiment, the coil is affixed to a non-movable member of the flowmeter. In another embodiment, the non-movable coil is affixed only to a spring sub-assembly which is affixed to the flow tubes which vibrate out-of-phase with respect to each other.

Abstract: A mass flowmeter has a flow tube inserted within the confines of a conduit containing a material flow. Mass flow information is derived for the material flow within the conduit by generating mass flow information for the material flowing within the smaller flow tube positioned within the conduit and then by adjusting the calculations for the flow tube to represent mass flow information for the conduit. In accordance with a first embodiment of the invention, a pressurized cover is positioned around the flow tube to isolate the exterior surface of the flow tube from the material in the conduit. The space between the exterior of the flow tube and the cover is pressurized to a pressure equal to that of the material in the conduit. Both sides of the flow tube walls are at the same pressure so that a flow tube comprised of thinner and more flexible material may be used.

Abstract: A Coriolis effect mass flowmeter for measuring mass material flow in a conduit. Elements of the meter are clamped directly onto an existing pipe or other conduit without diversion of the flow. The meter comprises a driver, such as a magnetostrictive driver, to oscillate a section of pipe between two supports. The driver is mounted on the pipe section at or near an anti-node of the second harmonic mode of the natural frequency of the pipe section. A sensor, such as an accelerometer, is mounted onto the pipe section at the node point of the second harmonic mode of the natural frequency of the pipe section during zero flow, (zero flow node point). The second sensor measures the amplitude of displacement of the zero flow node point due to the Coriolis effect forces from the mass of the material flowing through the oscillating pipe. This measurement is indicative of the mass flow rate of the material flowing through the pipe.

Abstract: Sample and hold circuits are used to detect a DC component of an AC signal on an amplifier's output to generate a feedback signal that is applied to the amplifier's input to cancel out a DC component of an AC input signal. The sample and hold circuits detect the peak excursions of the AC output signal and apply the stored peaks to averaging circuitry which determines the magnitude of the DC component of the output signal.

Abstract: An improved accuracy Coriolis mass flow meter. Signal processing embodiments provide improved accuracy by accounting for the non-linear relationship between phase angle difference of motion sensor signals and mass flow rate. Compensation is made for asymmetric and viscous damping effects, as well.

Abstract: A vibration densitometer having a permanent magnet biased magnetostrictive drive unit, a maximum efficiency, and an automatic search for a resonant frequency signal.

Abstract: A turbine flowmeter with an unusual radio frequency pick-up and non-magnetic, conductive turbine blades. The pickup includes a coil which is also a part of a tank circuit of an input oscillator. A phase lock loop is then employed which receives, as an input, the output of the input oscillator. When a turbine blade passes the pick-up, the input oscillator undergoes a frequency shift. Circuits connected from the phase lock loop output then produce pulses which are counted and indicated. The circuits may be constructed to cause an indicator to read in units of volume, i.e. the total volume flow through the flowmeter, if desired. The said circuits include two active filters, a Schmitt trigger, a current converter and an output circuit from the phase lock loop output.