Abstract: A thermal conductivity gauge implements a model of power dissipation to accurately measure gas pressure. An envelope surrounds a gas volume, and a sensor wire is positioned within the gas volume. The controller provides a model of power dissipation from the thermal conductivity gauge, including power loss due to conductive heat loss from sensor wire end contacts, radiative loss from the sensor wire toward the gas envelope, and pressure dependent conductive heat loss from the sensor wire through surrounding gas. The controller then applies a power input to the sensor wire to heat the sensor wire, and measures total power dissipation WT, sensor wire temperature Ts, and envelope temperature Te during the application of the power input. Gas pressure within the envelope is determined based on the measured WT, Ts and Te and the model of power dissipation.

Abstract: A gauge having a housing formed of a polymer material and one or more electrical feedthrough pins disposed in the housing. The electrical feedthrough pins can be oriented substantially perpendicular to each other and have complex shapes.

Abstract: A gauge having a housing formed of a polymer material and one or more electrical feedthrough pins disposed in the housing. The electrical feedthrough pins can be oriented substantially perpendicular to each other and have complex shapes.

Abstract: A gauge having a housing formed of a polymer material and one or more electrical feedthrough pins disposed in the housing. The electrical feedthrough pins can be oriented substantially perpendicular to each other and have complex shapes.

Abstract: A gauge having a housing formed of a polymer material and one or more electrical feedthrough pins disposed in the housing. The electrical feedthrough pins can be oriented substantially perpendicular to each other and have complex shapes.

Abstract: A gauge having a housing formed of a polymer material and one or more electrical feedthrough pins disposed in the housing. The electrical feedthrough pins can be oriented substantially perpendicular to each other and have complex shapes.

Abstract: A Long Lifetime Cold Cathode Ionization Vacuum Gauge Design with an extended anode electrode having an axially directed tip, a cathode electrode, and a baffle structure. The axially directed tip of the anode electrode can have a rounded exterior with a diameter at least 10% greater than the diameter of the anode electrode.

Abstract: A gauge having a housing formed of a polymer material and one or more electrical feedthrough pins disposed in the housing. The electrical feedthrough pins can be oriented substantially perpendicular to each other and have complex shapes.

Abstract: A Long Lifetime Cold Cathode Ionization Vacuum Gauge Design with an extended anode electrode having an axially directed tip, a cathode electrode, and a baffle structure. The axially directed tip of the anode electrode can have a rounded exterior with a diameter at least 10% greater than the diameter of the anode electrode.

Abstract: 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.

Abstract: 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.