Abstract: A system for measuring differences in a physical variable, such as temperature or voltage, by utilizing predictable behavior in the relative drift over time of reference curves representative of offset, and other measurement parameters for various circuit elements. In an initial calibration mode, the system records several reference curves, correlating ambient condition to offset, and, optionally, other parameter measurements acquired from circuit elements. These reference curves representing drift behavior, among electrical components, can be updated for time drift at a single, current arbitrary ambient temperature, the measurements for which can be obtained quickly and applied as a time drift correction to the reference curves, without interrupting normal system operation, to provide a compensated difference measurement between the different values of the physical variable.

Abstract: A system for measuring differences in a physical variable, such as temperature or voltage, by utilizing predictable behavior in the relative drift over time of reference curves representative of offset, and other measurement parameters for various circuit elements, including, for example, two sensors coupled to a difference signal amplifier, the difference signal amplifier, an ambient condition amplifier, and an analog to digital converter. In an initial calibration mode, the system records several reference curves, stored in memory, correlating ambient condition measurements to offset, and, optionally, other parameter measurements acquired from the difference signal amplifier and the ambient condition amplifier.

Abstract: A system for measuring differences in a physical variable, such as temperature or voltage, by utilizing predictable behavior in the relative time drift of offset curves for various circuit elements, including, for example, two sensors coupled to a difference signal amplifier, an ambient condition amplifier, and an analog to digital converter. In an initial calibration mode, the system records several offset curves, stored in memory, correlating ambient condition measurements to offset measurements acquired from the ambient condition amplifier and the difference signal amplifier. Offset curves recorded in the initial calibration mode, correlating ambient condition measurements to measurements from the difference signal amplifier, include one curve recorded with both inputs of the difference signal amplifier held at equal potential and another curve recorded with both sensors held at the same value of the physical variable, over a given ambient condition range.

Abstract: A system for measuring differences in a physical variable, such as temperature or voltage, by utilizing predictable behavior in the relative time drift of offset curves for various circuit elements, including, for example, two sensors coupled to a difference signal amplifier, an ambient condition amplifier, and an analog to digital converter. In an initial calibration mode, the system records several offset curves, stored in memory, correlating ambient condition measurements to offset measurements acquired from the ambient condition amplifier and the difference signal amplifier. Offset curves recorded in the initial calibration mode, correlating ambient condition measurements to measurements from the difference signal amplifier, include one curve recorded with both inputs of the difference signal amplifier held at equal potential and another curve recorded with both sensors held at the same value of the physical variable, over a given ambient condition range.

Abstract: A system for measuring differences in a physical variable, such as temperature, by utilizing predictable behavior in the relative time drift of offset curves for various circuit elements, including two sensors connected to a difference signal amplifier, an ambient condition amplifier, and an analog to digital converter. In an initial calibration mode, the system records several offset curves, stored in memory, correlating ambient condition measurements to offset measurements acquired from the ambient condition amplifier and the difference signal amplifier. Offset curves recorded in the initial calibration mode, correlating ambient condition measurements to measurements from the difference signal amplifier, include one curve recorded with both inputs of the difference signal amplifier held at equal potential and another curve recorded with both sensors held at the same value of the physical variable, over a given ambient condition range.

Abstract: A portable interactive electro-optic data input/output, processing, storage, and display device responsive to hand printed text and hand drawn graphics. The device preferably comprises a combined flat panel display and input pen sensing surface constructed from non-mechanical, non-emissive display elements, such as liquid crystal display elements. The device also comprises an input pen for manual entry of hand printed text and hand drawn graphics, as well as commands, directly onto the display surface for providing an electronic writing and drawing slate. The display elements themselves are preferably utilized as input pen sense locations. The flat panel display and input pen sensing surface is constructed so that there is no display distortion when the input pen is in contact with the surface. Rapid input pen sensing is provided for accommodating natural pen movement on a high resolution, large area display.

Abstract: A portable interactive electro-optic data input/output, storage, processing, and display device responsive to hand printed text and hand drawn graphics. The device preferably comprises a combined flat panel display and pen sensing surface constructed from non-mechanical, non-emissive display elements, such as liquid crystal display elements. The device also comprises an input pen for manual entry of hand printed text and hand drawn graphics, as well as commands, directly onto the display surface for providing an electronic writing and drawing slate. The display elements themselves are preferably utilized as input pen sense locations. The flat panel display and pen sensing surface is constructed so that there is no display distortion when the input pen is in contact with the surface. Rapid input pen sensing is provided for accommodating natural pen movement on a high resolution, large area display.