Abstract: A motor-driven roller disc for multi-directional operation under the control of a user, with a multi-wheeled drive configuration with motorized direct-drive power-train to give a user the ability to move in any direction at any time, and to maintain control over steering and speed when in motion. The roller disc includes a platform having an array of radially-oriented wheels mounted around the underside perimeter, and a central pivot wheel mounted at the center of the underside. The central pivot wheel maintains a slightly higher clearance than the perimeter wheels, enabling the user to engage a desired perimeter wheel by shifting his/her weight towards it, thereby making contact with the ground. All of the perimeter wheels are connected to a common flexible/jointed axle that encircles the disc, the axle being driven by a battery-powered DC motor.

Abstract: A novel scanning monochromator uses a PM stepper-motor to directly drive a diffraction grating. By employing interpolated encoder feedback in combination with the PM stepper-motor feedback, a resolution of over 250,000 pulsed steps is available for each revolution of the PM stepper-motor. This translates into more than 20,000 incremental angular-displacement steps over a usable 30° range of dispersion-element rotation. High field accuracy is achieved by a direct PM stepper-driven diffraction grating, and a unique calibration approach based on Wood's anomalies. A plurality of diffracted light beams emerge from the oscillating grating, and these are scanned past a detector for detection, whereby the relative rotation information of the grating can be detected with great accuracy. A number of tolerance-correcting measures are also included to yield an extremely accurate, self-lubricating scanning monochromator that can be economically produced.

Abstract: A motor-driven roller disc for multi-directional operation under the control of a user, with a multi-wheeled drive configuration with motorized direct-drive power-train to give a user the ability to move in any direction at any time, and to maintain control over steering and speed when in motion. The roller disc includes a platform having an array of radially-oriented wheels mounted around the underside perimeter, and a central pivot wheel mounted at the center of the underside. The central pivot wheel maintains a slightly higher clearance than the perimeter wheels, enabling the user to engage a desired perimeter wheel by shifting his/her weight towards it, thereby making contact with the ground. All of the perimeter wheels are connected to a common flexible/jointed axle that encircles the disc, the axle being driven by a battery-powered DC motor.

Abstract: A novel scanning monochromator uses a PM stepper-motor to directly drive a diffraction grating. By employing interpolated encoder feedback in combination with the PM stepper-motor feedback, a resolution of over 250,000 pulsed steps is available for each revolution of the PM stepper-motor. This translates into more than 20,000 incremental angular-displacement steps over a usable 30° range of dispersion-element rotation. High field accuracy is achieved by a direct PM stepper-driven diffraction grating, and a unique calibration approach based on Wood's anomalies. A plurality of diffracted light beams emerge from the oscillating grating, and these are scanned past a detector for detection, whereby the relative rotation information of the grating can be detected with great accuracy. A number of tolerance-correcting measures are also included to yield an extremely accurate, self-lubricating scanning monochromator that can be economically produced.

Abstract: A method for high speed spectroscopic constituent verification. The method includes the steps of illuminating a sample with broadband light and measuring two preselected wavelengths of reflected light: a first narrow-range of wavelengths &lgr;1 that is not significantly absorbed by the constituent of interest, and a second narrow-range of wavelengths &lgr;2 that is substantially absorbed by the constituent of interest. Given the two measurements of reflection, upper and lower thresholds are determined (the latter based on a percentage of the measured baseline reflected light of wavelengths &lgr;1). Finally, the presence of the constituent of interest is indicated if the measure of the reflected discriminant wavelength &lgr;1 is within the upper and lower threshold measures of reflected baseline light &lgr;1.

Abstract: A method and device for high speed spectroscopic constituent verification. The method includes the steps of illuminating a sample with broadband light and measuring two preselected wavelengths of reflected light: a first narrow-range of wavelengths .lambda.1 that is not significantly absorbed by the constituent of interest, and a second narrow-range of wavelengths .lambda.2 that is substantially absorbed by the constituent of interest. Given the two measurements of reflection, upper and lower thresholds are determined (the latter based on a percentage of the measured baseline reflected light of wavelengths .lambda.1). Finally, the presence of the constituent of interest is indicated if the measure of the reflected discriminant wavelength .lambda.1 is within te upper and lower threshold measures of reflected baseline light .lambda.1.