AVS 56th International Symposium & Exhibition
    Vacuum Technology Monday Sessions
       Session VT-MoA

Paper VT-MoA8
Instrument Design for an Integrated Total and Partial Pressure High Speed Vacuum Quality Monitor Sensor

Monday, November 9, 2009, 4:20 pm, Room C1

Session: Pressure, Partial Pressure, and Flow Measurement
Presenter: M. Schott, Brooks Automation Inc.
Authors: M. Schott, Brooks Automation Inc.
J. Rathbone, Brooks Automation Inc.
P. Sandt, Brooks Automation Inc.
K. Van Antwerp, Brooks Automation Inc.
Correspondent: Click to Email
Design details and performance test results of an integrated total and partial pressure high speed vacuum quality monitor instrument will be presented. A single-sensor, high-speed total pressure and partial pressure instrument has been developed with a 1-100amu, 100ms update rate. The complex sensor is comprised of a hot-filament ion source, electrostatic ion-trap mass separator, Shulz-Phelps based total pressure detector, and an electron multiplier ion detector that is shared for both UHV total pressure and ratiometric partial pressure measurements. A dual board electronics instrument package has been designed to control, drive and process complex sensory data, and output the processed data into a usable form within the cycle time of the measurement update rate. High speed data processing and real time sensor control was achieved by dividing the sensory control and measurement function from the data reduction and host input/output functions. The mass spectrometer interface (MSI) electronics board utilizes a local uC, which directly controls and provides system status on the following sensory functions: multiple ion-trap bias voltages, filament power & emission current, ion-trap mass analyzer RF drive amplitude & frequency and ion current electrometers. The MSI local processor accepts serial high-level commands from the host input/output (HIO) board processor, which predetermines the sensory “scan” control parameters. The HIO board performs data reduction and user input/output. HIO data reduction algorithms process the raw sensory data into usable total and partial pressure [amu, amplitude] matrix data. All resulting in hard-coded and/or custom user outputs, which may produce a number of real-time and non-real-time datum.