Abstract: A method for linearizing the sensitivity of a quadrupole mass spectrometric system to allow the sensor to more accurately report partial pressures of a gas in high pressure areas in which the reported data is effected by a number of loss mechanisms. According to the invention, correction factors can be applied empirically or software in a quadrupole mass analyzer system can be equipped with correcting software to expand the useful range of the mass spectrometer.

Abstract: A method for manufacturing a miniature quadrupole from a single blank includes fastening four lengthwise insulating strips into parallel slots formed in the blank. A lengthwise axial hole is cut through the blank for the guide wire used in the EDM process. The blank is machined lengthwise into four electrodes using the EDM process so that the electrodes are spaced apart in a widthwise direction and each electrode is connected to an adjacent electrode by one of the insulating strips. During the cutting, the electrodes are held in place by the insulating strips.

Abstract: A miniaturized ion source for a mass spectrometer includes a anode and a focus plate whose interior surfaces form an ionization volume for a retained gas sample. Molecules of the gas sample are ionized by electrons, and the resulting ions are concentrated and converged through an exit aperture in the focus plate to the entrance of an ion analyzer, such as a quadrupole mass filter. Preferably, at least one of the anode and the focus plate includes a curved interior surface which converges the formed ions into a focused beam for directing into the ion analyzer. In addition, the thickness of the exit aperture of the focus plate and or the setback of the focus plate relative to the anode ensures that no line of sight exists between the interior surface of the anode from which ion-forming electrons can scatter into the adjacent ion analyzer.

Abstract: A mass spectrometer gas analyzer includes an ion source for producing ions of a sample gas in a defined ion volume. An ion analyzer collects and analyzes a first portion of the produced ions to determine a partial pressure for a selected gas species within the sample gas. An oppositely disposed ion collector collects a second portion of the ions to determine a total pressure of the contained gas sample. A collecting surface of the ion collector is positioned relative to the incoming ion beam to allow collection of ion current but the surface is configured such that a substantial portion of a plurality of secondary electrons produced by ion bombardment with the ion collector are deflected away from the ionization volume. The partial pressure is thus determined by the ion analyzer without secondary electrons entering the ion analyzer.

Abstract: A dual beam ion source comprises an ion volume in an ion chamber, an ion collector, and two identical ion accelerators. One ion accelerator accelerates a first, "test" ion stream from the ion volume in a first direction and directs it to the ion collector where it can be directly measured. The second ion accelerator accelerates a second, "utilizable" ion stream from the ion volume in a second direction. By directly measuring the ion current (caused by the first, "test" ion stream) at the ion collector, either or both the total ion pressure of the gas within the ion volume, and the magnitude of the second, "utilizable" ion stream, can be calculated.

Abstract: A multi-stage valve having a valve housing containing an inlet port and an outlet port that communicate through means of an elongated chamber formed in the housing. An outer sealing unit is mounted in the chamber and is adapted to close in sealing contact against one of the ports. A control orifice is passed through the first sealing unit to restrict the flow through the port when the unit is sealed thereagainst. A second inner sealing unit is mounted in the chamber behind the outer unit and is arranged to close thereagainst to seal the orifice. The two units are coupled by a lost motion mechanism which permits the sealing units to close in sequence between a fully closed position, an intermediate position wherein the flow through the valve is restricted by the orifice and a fully opened position wherein the flow through the valve is unrestricted.

Abstract: A method for linearizing the sensitivity of a quadrupole mass spectrometric system to allow the sensor to more accurately report partial pressures of a gas in high pressure areas in which the reported data is effected by a number of loss mechanisms. According to the invention, correction factors can be applied empirically or software in a quadrupole mass analyzer system can be equipped with correcting software to expand the useful range of the mass spectrometer.