Abstract:
Sensors and/or transducers can exhibit nonlinear response to temperature changes in terms of offset and also in terms of sensitivity to variations in a sensed physical attribute (pressure, strain, displacement, etc.). Padé Approximant function emulators are used to model the nonlinear offset and/or nonlinear sensitivity behaviors of a given sensing means relative to one or more temperature sub-ranges and to produce temperature compensating corrections for both offset and sensitivity as may be desired. In order to avoid use of brute force division for generating the Pade' Approximant function signals, in one set of embodiments, feedback is used to provide a corresponding effect. In order to minimize the number of coefficients that are to be resolved and stored, in one set of embodiments, first or higher order Pade' Approximants with normalized denominators are used so that each function can be defined with just three coefficients. Embodiments that are more analog in nature or more digital in nature are disclosed. Methods for resolving the Pade' Approximant coefficients and calibrating each sensor unit on a mass production basis are also disclosed.
Abstract:
L'invention concerne un dispositif de contrôle non destructif comprenant un boîtier de contrôle (2) relié à un module de mesure (10) . Ce dispositif comporte en outre un port de communication (12) permettant simultanément, le pilotage du boîtier de contrôle (2) par un dispositif externe de traitement de données (20) , l'alimentation électrique dudit boîtier (2) et le transfert de données de mesures provenant dudit module de mesure (.10) vers le dispositif externe de traitement de données (20) .
Abstract:
An optical sensor system (20) has an optical detector (28) with an active detector area (38) and a detector output signal (40). A test-signal optical source (44) has a controllable optical source (48) having an output of a wavelength detectable by the optical detector (28), and a test-signal director (50) that directs the output of the optical source (48) to the active detector area (38) of the optical detector (28). A housing (22) encloses the optical detector (28) and the test-signal optical source (44). A test instrumentation controller (52) controls the operation of the optical source (48), and receives the detector output signal (40) for evaluation.
Abstract:
An electronic gas sensor signal conditioner which can automatically adapt to a wide variety of commercial off-the-shelf sensors and provide a digital output in a standard, easily used format. The signal conditioner has analog and digital sections. The analog section includes a sensor excitation sub-section and a signal amplification sub-section. The digital section comprises a microcontroller and controls the analog section. The digital section also converts the signal from the analog section into digital form, reads the sensor TEDS (Transducer Electronic Data Sheet), applies calibration constants and converts the signal into a standard, easily readable digital format.
Abstract:
The present invention provides improved methods and systems for laser beam positioning, shape profile, size profile, drift, and/or deflection calibration using an image capture device, such as a microscope camera, for enhanced calibration accuracy and precision. The methods and systems are particularly suited for iris calibration and hysteresis measurement of a variable diameter aperture. One method for calibrating laser pulses from a laser eye surgery system using an image capture device comprises imaging a known object with an image capture device. A pulsed laser beam is directed onto a calibration surface so as to leave a mark on the calibration surface. The mark on the calibration surface is then imaged with the image capture device. The laser eye surgery system is calibrated by comparing the image of the mark on the calibration surface to the image of the known object.
Abstract:
A method and apparatus for rendering a plurality of objects. The method includes receiving ray differential information associated with a ray, determining a resolution associated with a surface patch based on at least information associated with the ray and the surface patch, generating a geometry representation based on at least information associated with the surface patch and the resolution, and determining whether the ray and the surface patch intersect based on at least information associated with the ray and the geometry representation. The determining a resolution includes processing information associated with the ray and the surface patch, determining a ray differential based on at least information associated with the ray and the surface patch, processing information associated with the ray differential and the surface patch, and determining the resolution based on at least information associated with the ray differential and the surface patch.
Abstract:
Methods of reducing the effects of measurement device artifacts on a measurement of a sample are presented. A number of reference measurements performed with the measurement device are observed to identify reference independent components of the reference measurements. The variations of the reference independent components are used as surrogates for possible a artifacts of the measurement device. A number of measurements of subjects similar to the sample are observed, and similarity components of the subject measurements that vary in a manner similar to the reference independent components may be identified. The sample measurement is then adjusted to remove at least part of the similarity components that correspond to the variations in the reference independent components. The adjustment of the sample measurement is thereby improved by reducing the effects of artifacts of the measurement device.
Abstract:
A real, physical radiation phantom for simulating a portion of a human being includes a body portion providing an analytic outer shape of the phantom, the outer shape being similar to a shape of at least a portion of the human being, the body portion having a first physical characteristic of a first value similar to a second value of the first physical characteristic corresponding to human soft tissue, and at least one internal component disposed in the body, the internal component having an analytic shape approximating an internal portion of human anatomy and having a third value of the first physical characteristic different from the first value.
Abstract:
Systems and methods for digitally controlling sensors. In one embodiment, a digital controller for a capacitance diaphragm gauge is embedded in a digital signal processor (DSP). The controller receives digitized input from a sensor AFE via a variable gain module, a zero offset module and an analog-to-digital converter. The controller automatically calibrates the received input by adjusting the variable gain and zero offset modules. The controller also monitors and adjusts a heater assembly to maintain an appropriate temperature at the sensor. The controller utilizes a kernel module that allocates processing resources to the various tasks of a gauge controller module. The kernel module repetitively executes iterations of a loop, wherein in each iteration, all of a set of high priority tasks are performed and one of a set of lower priority tasks are performed. The controller module thereby provides sensor measurement output at precisely periodic intervals, while performing ancillary functions as well.
Abstract:
A method and apparatus for calibrating a sensor for determination of the concentration of a sterilant, e. g., hydrogen peroxide vapor, in a sterilization system. This invention provides a method for calibrating a sensor that is used for measuring the quantity of a sterilant in a system for delivering the sterilant, the method comprising the steps of: (a) generating reference calibration data, the reference calibration data showing a mathematical relationship between a measurable parameter, e. g. voltage, and a quantity of the sterilant, e. g., parts of sterilant per million parts of air (ppm), for a plurality of sensors; (b) generating sensor calibration data, the sensor calibration data showing a mathematical relationship between the measurable parameter and the quantity of the sterilant for an individual sensor; and(c) normalizing the sensor calibration data to compensate for the difference between the measurable parameter for the reference calibration data and the measurable parameter for the sensor calibration data, whereby data obtained by the individual sensor can be used to accurately determine the quantity of sterilant in the system.