Patents Assigned to ADE Technologies
  • Patent number: 6714023
    Abstract: A non-contact capacitive displacement measurement gage that provides high accuracy displacement measurements of well-connected targets and poorly-connected targets. The capacitive displacement measurement gage includes a capacitive probe, first and second amplifiers, and a signal generator. The capacitive probe includes a sensor electrode, a guard electrode, and a compensating electrode. The signal generator provides a predetermined voltage signal directly to the sensor electrode, to the guard electrode through the first amplifier having unity gain, and to the compensating electrode through the second amplifier having a predetermined transfer function. The second amplifier assures that substantially zero current is driven into the target element by the probe during gage operation, thereby allowing highly accurate displacement measurements of target elements having unknown or poorly controlled impedance.
    Type: Grant
    Filed: January 29, 2003
    Date of Patent: March 30, 2004
    Assignee: ADE Technologies
    Inventor: Roy E. Mallory