Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A method and apparatus for measuring gas pressure by combining an ionization gauge with at least one other vacuum sensor. Nonvolatile memory coupled to the vacuum gauge contains calibration parameters unique to each individual sensor based on factory calibration. The nonvolatile memory may contain calibration parameters for a heat-sensitive vacuum sensor to compensate for the temperature gradients generated by the ionization gauge. The calibration parameters are a function of calibration data determined when the ionization gauge is both on and off. The nonvolatile memory may store a window of measurement data of the vacuum gauge that is updated at predetermined time intervals and in response to an event, such as an error event, to aid in investigating the cause of vacuum gauge malfunction or failure.

Abstract: A method and apparatus for operating a multi-hot-cathode ionization gauge is provided to increase the operational lifetime of the ionization gauge in gaseous process environments. In example embodiments, the life of a spare cathode is extended by heating the spare cathode to a temperature that is insufficient to emit electrons but that is sufficient to decrease the amount of material that deposits on its surface or is optimized to decrease the chemical interaction between a process gas and a material of the at least one spare cathode. The spare cathode may be constantly or periodically heated. In other embodiments, after a process pressure passes a given pressure threshold, plural cathodes may be heated to a non-emitting temperature, plural cathodes may be heated to a lower emitting temperature, or an emitting cathode may be heated to a temperature that decreases the electron emission current.

Abstract: A method and apparatus for operating a multi-hot-cathode ionization gauge is provided to increase the operational lifetime of the ionization gauge in gaseous process environments. In example embodiments, the life of a spare cathode is extended by heating the spare cathode to a temperature that is insufficient to emit electrons but that is sufficient to decrease the amount of material that deposits on its surface or is optimized to decrease the chemical interaction between a process gas and a material of the at least one spare cathode. The spare cathode may be constantly or periodically heated. In other embodiments, after a process pressure passes a given pressure threshold, plural cathodes may be heated to a non-emitting temperature, plural cathodes may be heated to a lower emitting temperature, or an emitting cathode may be heated to a temperature that decreases the electron emission current.

Abstract: A method and apparatus for operating a multi-hot-cathode ionization gauge is provided to increase the operational lifetime of the ionization gauge in gaseous process environments. In example embodiments, the life of a spare cathode is extended by heating the spare cathode to a temperature that is insufficient to emit electrons but that is sufficient to decrease the amount of material that deposits on its surface or is optimized to decrease the chemical interaction between a process gas and a material of the at least one spare cathode. The spare cathode may be constantly or periodically heated. In other embodiments, after a process pressure passes a given pressure threshold, plural cathodes may be heated to a non-emitting temperature, plural cathodes may be heated to a lower emitting temperature, or an emitting cathode may be heated to a temperature that decreases the electron emission current.

Abstract: A method and apparatus for operating a multi-hot-cathode ionization gauge is provided to increase the operational lifetime of the ionization gauge in gaseous process environments. In example embodiments, the life of a spare cathode is extended by heating the spare cathode to a temperature that is insufficient to emit electrons but that is sufficient to decrease the amount of material that deposits on its surface or is optimized to decrease the chemical interaction between a process gas and a material of the at least one spare cathode. The spare cathode may be constantly or periodically heated. In other embodiments, after a process pressure passes a given pressure threshold, plural cathodes may be heated to a non-emitting temperature, plural cathodes may be heated to a lower emitting temperature, or an emitting cathode may be heated to a temperature that decreases the electron emission current.

Abstract: A method and apparatus for measuring gas pressure by combining an ionization gauge with at least one other vacuum sensor. Nonvolatile memory coupled to the vacuum gauge contains calibration parameters unique to each individual sensor based on factory calibration. The nonvolatile memory may contain calibration parameters for a heat-sensitive vacuum sensor to compensate for the temperature gradients generated by the ionization gauge. The calibration parameters are a function of calibration data determined when the ionization gauge is both on and off. The nonvolatile memory may store a window of measurement data of the vacuum gauge that is updated at predetermined time intervals and in response to an event, such as an error event, to aid in investigating the cause of vacuum gauge malfunction or failure.

Abstract: The present invention is directed to a Coriolis-type flowmeter having a dynamic counterbalance system which comprises a flowtube through which a fluid to be measured is permitted to flow; the flowtube comprising first and second ends; a counterbalance which is vibrationally coupled to the flowtube proximate the first and second ends; an electromagnet device for vibrating the flowtube and the counterbalance in opposition to one another; the flowtube having a first frequency response to the vibrating means and the counterbalance having a second frequency response to the vibrating means; at least one inertial mass; and means for selectively coupling the inertial mass to the counterbalance to thereby alter the second frequency response by a desired amount; wherein in the event the second frequency response is different from the first frequency response, the inertial mass may be coupled to the counterbalance to alter the second frequency response by the desired amount to thereby make the second frequency response

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A dynamic sweeping mechanism which drives a line-scan camera's field of view in a direction which is substantially perpendicular to the scan direction. The operation of the dynamic sweeping mechanism enables the line scan camera to make multiple scans across a target, providing the image processor the necessary image information to generate a two-dimensional image of the object as well as positioning the line scan camera at an optimal angle of view to obtain accurate single scan image data. The scan line angle of view is dynamically swept in a rotational manner about an axis of rotation which is parallel to the scan line under the control of either a dedicated drive mechanism or coupled to pre-existing drive mechanisms in the robotic hand mechanism.

Abstract: A bar code conversion system and method identifies good data in the scan data array and analyzes that data to generate machine-interpretable code. A vision system optically scans bar code labels and places the resulting digital camera data into a two dimensional line scan data array of pixels. A process.sub.-- line function then searches the scan data array for three lines that intersect the initial bars and spaces of the bar code (called starting lines) and 3 lines that intersect the last bars and spaces (called ending lines). For each pair of starting and ending lines, a build.sub.-- composite generates a composite line using pixels in positions between the first pixel of a starting line and the last pixel of a corresponding ending line. A run.sub.-- length decode function is then invoked on each composite line to create a run length array of width values, each of which indicates the width (in pixels) of a bar or space of the bar code. Using statistical analysis, a convert.sub.-- bars.sub.-- and.sub.

Abstract: A method and apparatus are described for on-the-fly cataloging of library cell contents in an automated robotic tape library. This method decouples the robotic arm motion/tape cartridge label scanning process from the image processing software/hardware. In accordance with the present invention, tape cartridge label images are captured at a library system processor priority which is higher than the priority of the image processing task. These captured images are stored in a circular buffer while image processing continues to take place in a lower priority task. Both the image processing system hardware and software are asynchronous with respect to the velocity of the robotic arm used to scan the tape cartridge cells. The scanning velocity of the robotic arm can be maximized with respect to purely mechanical, electrical, or optical camera considerations and is independent of the library system processor image processing speed.

Abstract: A robotic arm calibration system is described which comprises a video line scan camera vision system used in conjunction with a plurality of novel "N"-shaped targets in an automated tape storage library. The targeting system of the present invention provides, with a single horizontal video scan of the target, all of the data necessary to enable calculation of a reference point of the robotic arm with respect to each target to thereby obtain precise robotic arm calibration in relationship to the library system workspace. The position of the robotic arm is determined using the vision system in conjunction with calibration targets which are located within the tape cartridge library, in addition to a target located on the robotic arm. The present system functions independently of the spacing between the arm retrieval mechanism and the tape cartridge storage cells.