Direct Measurement Corporation

Mks Instruments, Inc.

Concentric Meter Corporation

Brooks Automation Gmbh

Michael N Schott

Donald Reed Cage

Gerardo A Brucker

Larry K Carmichael

Kristian S Schartau

Timothy C Swinney

Brandon J Kelly

David T Hahn

Kenneth D Van Antwerp, Jr

Alfred A Funari

Jesse A Weber

John H Henry

Scott C Heinbuch

Barbara Jane Hinch

G Jeffery Rathbone

Alexei Victorovich Ermakov

Alexei V Ermakov

A cold cathode ionization vacuum gauge includes an extended anode electrode and a cathode electrode surrounding the anode electrode along its length and forming a discharge space between the anode electrode and the cathode electrode. The vacuum gauge further includes an electrically conductive guard ring electrode interposed between the cathode electrode and the anode electrode about a base of the anode electrode to collect leakage electrical current, and a discharge starter device disposed over and electrically connected with the guard ring electrode, the starter device having a plurality of tips directed toward the anode and forming a gap between the tips and the anode.

Cold cathode ionization vacuum gauge

An example fluid parameter sensor and meter is disclosed to measure at least one parameter of a fluid. In an example, the fluid parameter meter includes an outer conduit. A sensor element assembly is disposed in the outer conduit and having a plurality of sensor elements to convey the fluid inside of the sensor element assembly. At least one mounting flexure is fixedly attached to the sensor element assembly and to the outer conduit. The at least one mounting flexure is configured to enable the sensor element assembly to vibrate in a radial motion. At least one vibration driver causes the sensor element assembly to vibrate in the radial motion. At least one vibration sensor senses the radial motion of the sensor element assembly. Controlling electronics measure at least one parameter of a fluid based on said radial motion.

Fluid parameter sensor and meter

An electromagnetic transducer is disclosed. An example electromagnetic transducer may be provided for a fluid parameter meter. The example electromagnetic transducer may include at least one permanent magnet, a first armature mounted in magnetic cooperation with the permanent magnet, and a second armature mounted in magnetic cooperation with the permanent magnet. The first and the second armatures are arranged to interact with a third armature in magnetic cooperation with the first armature and the second armature. The example electromagnetic transducer may also include at least one electric coil mounted in cooperation with the magnetic field so that electric current through the electric coil to vary the vibratory forces. The example electromagnetic transducer may include an electronic module to control electric current and vibratory forces on a vibrating element of the fluid parameter meter.

Electromagnetic transducer

An example fluid parameter sensor and meter is disclosed to measure at least one parameter of a fluid. In an example, the fluid parameter meter includes an outer conduit. A sensor element assembly is disposed in the outer conduit and has at least one straight uniform sensor element with an open interior to convey the fluid inside of the sensor element assembly. At least one mounting flexure is fixedly attached to the sensor element assembly and to the outer conduit. The at least one mounting flexure is configured to enable the sensor element assembly to vibrate in a natural radial mode shape of vibration. At least one vibration driver causes the sensor element assembly to vibrate. At least one vibration sensor senses the vibration of the sensor element assembly.

An ionization gauge that measures pressure has an electron source that emits electrons, and an anode that defines an ionization space. The gauge also includes a collector electrode to collect ions formed by an impact between the electrons and a gas and to measure pressure based on the collected ions. The electron source is dynamically varied in emission current between a plurality of emission levels dependent on pressure and a second parameter other than pressure. The ionization gauge may also vary various operating parameters of the gauge components according to parameters stored in a non-volatile memory and selected by a user.

Ionization gauge with emission current and bias potential control

An ion trap includes an electrode structure, including a first and a second opposed mirror electrodes and a central lens therebetween, that produces an electrostatic potential in which ions are confined to trajectories at natural oscillation frequencies, the confining potential being anharmonic. The ion trap also includes an AC excitation source having an excitation frequency f that excites confined ions at a frequency of about twice the natural oscillation frequency of the ions, the AC excitation frequency source preferably being connected to the central lens. In one embodiment, the ion trap includes a scan control that mass selectively reduces a frequency difference between the AC excitation frequency and about twice the natural oscillation frequency of the ions.

Electrostatic ion trap

A system for, and method of, compensating for a boundary condition effect on a Coriolis meter having (at least) two sensors for generating preliminary signals that are a function of fluid flow through the meter and a Coriolis meter employing the system or the method. In one embodiment, the system includes: (1) signal combination circuitry, couplable to the (at least) two sensors, that develops an imaginary difference signal based on the preliminary signals and (2) boundary effect compensation circuitry, coupled to the signal combination circuitry, that calculates a boundary effect compensation factor based on the imaginary difference signal.

System and method for employing an imaginary difference signal component to compensate for boundary condition effects on a Coriolis mass flow meter

A signal processing apparatus and method for measuring a mass flow rate of a fluid flowing in conjunction with a surface of a Coriolis mass flow meter and a field-provable Coriolis mass flow meter. The apparatus includes: (1) a driver for creating a prescribed vibration in the surface, (2) a motion sensor for measuring a motion of the surface, (3) response characteristic determination circuitry, coupled to the motion sensor, for determining a response characteristic of the surface and (4) flow rate calculation circuitry, coupled to the response characteristic determination circuitry, for calculating a measured mass flow rate of the fluid as a function of the motion and the response characteristic. The field-provable meter employs the response characteristic to monitor or compare meter performance without requiring a separate proving device.

Signal processing and field proving methods and circuits for a coriolis

In the field of Coriolis mass flow meters, determination of the true zero of the meter has always been problematic due to zero drift effects with changing boundary conditions and fluid parameters. Disclosed are apparatus and methods for determining the true mass flow related component of the signal of the meter separately from errors caused by changing boundary conditions and fluid parameters. Accordingly, an apparatus for measuring a mass flow rate of a fluid flowing relative to a flow conduit includes: (1) a force driver for vibrating the flow conduit, (2) a sensor for measuring a resulting motion of the flow conduit and producing a sensed motion signal indicative thereof, the resulting motion containing a Coriolis mode component and a boundary condition mode component, (3) signal processing circuitry, coupled to the sensor to receive the sensed motion signal therefrom, for determining a magnitude of the Coriolis mode component of the resulting motion and (4) output circuitry for producing an output signal proportional to the mass flow rate, the output signal substantially free of influence from the boundary condition mode component of the sensed motion signal.

Signal processing apparati and methods for attenuating shifts in zero

Several Radial Mode Coriolis mass flow rate meter geometries and electronic circuits are described that may be made to be sensitive to pressure or density changes. In one embodiment, the meter comprises: (1) a flow conduit for containing a fluid having a physical characteristic, the fluid adapted to flow in the conduit at an unknown rate, (2) a drive circuit for creating a vibration in the flow conduit, the fluid altering the vibration as a function of the physical characteristic and the flow rate, (3) a detector circuit for measuring the altered vibration at a working point and producing a signal representing an uncompensated mass flow rate of the fluid and (4) a computation circuit for calculating a compensated mass flow rate of the fluid proportional to the uncompensated rate by 1/.OMEGA.1.sup.n, where .OMEGA.1 is a driven natural frequency of the flow conduit and n is a number chosen as a function of the working point, the compensated rate thereby reduced of effects of the physical characteristic. A unique mathematical algorithm is also described that allows for a much wider variety of design geometry while maintaining insensitivity to pressure or density without having to measure or compensate for either. In addition, a method is described that allows for the accurate measurement and compensation of both pressure and density.

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Loveland, CO, United States of America

Michael N Schott