摘要:
A representative positron emission tomography (PET) calibration system includes a PET scanner having a ring detector, a phantom that is placed at approximately the center of the ring detector, and a time alignment calibration manager that is coupled to the PET scanner. The time alignment calibration manager detects coincidence events from the phantom, calculates position of time of flight events from the ring detector based on the detected coincidence events, and calculates time offsets for the ring detector using a mean value calculation based on the calculated position of the time of flight events.
摘要:
The invention provides a method and system for calibrating an instrument pointer driven by an electric motor against a mechanical stop without using feedback control. According to the invention, the system for calibrating said instrument pointer comprises a pointer (8) engageable with the electric motor (2) including an intermediate gear (3) for driving the pointer (8). A stop means (5) is positioned at a desired reference point where, in a first powered state, the motor (2) is accelerated at a maximum torque for a first predetermined radial distance to move said pointer (8) towards a position whereat said stop means (5) is engaged. The motor (2) is then re-accelerated at a reduced torque for a second predetermined radial distance, whereby the pointer (3) is caused to be moved and held against the stop means (5).
摘要:
A method and system for calibrating analog integrated circuits. Initially, a single calibration circuit is formed integral with a group of analog integrated circuits. A control signal and a calibration signal are generated from the calibration circuit. Next, the control signal and the calibration signal are selectively coupled to an input of a particular analog integrated circuit among the group of analog integrated circuits. The particular analog integrated circuit is then selected for calibration via the control signal. An output of the particular analog integrated circuit is thereafter observed, in response to enabling the particular analog integrated circuit for calibration via the control signal, such that if an output of the particular analog integrated circuit corresponds to the calibration signal, a successful calibration of the particular analog integrated circuit is indicated, thereby permitting the single calibration circuit to generically calibrate a multitude of diverse analog integrated circuits. The output of the particular analog integrated circuit is coupled to an input of the single calibration circuit, and the calibration value is incremented until the particular analog integrated circuit is calibrated, such that upon completion of the calibration, the calibration value comprises a current calibration value associated with the particular analog integrated circuit. In addition, if the output of the particular analog integrated circuit is composed of a logically high value, then an indication is provided that the particular analog integrated circuit has been successfully calibrated.
摘要:
In a pH measuring instrument, automatic calibration (sloping) is performed by placing the pH electrode in a standard solution, dialing the pH of this standard solution into a decade thumb wheel switch, and depressing the slope switch. The measurement voltage from the electrode is converted to a binary coded digital signal. This signal and the digital signal from the thumb wheel switch are applied to a binary adder which produces a multiple bit output representing the difference. Clock pulses are supplied to a reversible digital counter which counts in a direction specified by the most significant bit of the binary adder output. The count in the reversible counter, representing the error, is converted to an analog signal which is used to control the reference voltage in a ratio system to produce a calibrated reading. The supply of clock pulses to the counter is automatically stopped when the error is zero.
摘要:
A correlation standard for calibrating a scanning electron microscope is provided. The correlation standard comprises a pellet and a metal stub. The pellet comprises a compressed mixture of carbon powder and alumina powder. The pellet is attached to the metal stub with a conductive adhesive.
摘要:
A representative positron emission tomography (PET) calibration system includes a PET scanner having a ring detector, a phantom that is placed at approximately the center of the ring detector, and a time alignment calibration manager that is coupled to the PET scanner. The time alignment calibration manager detects coincidence events from the phantom, calculates position of time of flight events from the ring detector based on the detected coincidence events, and calculates time offsets for the ring detector using a mean value calculation based on the calculated position of the time of flight events.
摘要:
The Field Testing Instrument (FTI) is designed for use in the regular maintenance and installation of airport Precision Approach Path Indicator (PAPI). The FTI is a self-contained and portable instrument that accurately measures the most important PAPI parameters, such as vertical aiming angle, transition angle, and light intensity. In addition to working with the current incandescent PAPIs, the FTI also measures parameters specific to the next generation LED PAPI. The FTI uses modern, efficient technology to reduce the life-cycle cost of approach lighting systems. The FTI improves on traditional PAPI testing methods by directly measuring the PAPI light beam focused to a target plate, as if seen from the pilot perspective. Due to significantly improvements in measurement accuracy and reliability, the FTI may supplement and even replace costly flight checks for PAPI maintenance with ground based operation.
摘要:
A black body assembly is provided for use in the calibration of infrared cameras. The assembly includes, among other things, a housing within which calibration components may be situated, and a lens guide for accurately positioning the assembly over a lens of the infrared camera. A heat emitter may be positioned within the housing for emitting a necessary amount of heat for calibration purposes. A heating element may also be provided within the housing for controlling the heating and cooling of the heat emitter. The assembly may also include a heat sink to remove excessive heat generated from the thermoelectric cooler during temperature cycling. An arm may be employed to hingedly connect the assembly to the camera to provide reliable and repeatable way to position the black body assembly at the front of the infrared lens. A method for calibrating an infrared camera is also provided.
摘要:
A system calibrates a solid state detector (20) for a radiation imaging device (10) in a single acquisition. A calibration phantom (40) emits radiation concurrently at at least first and second characteristic energy levels. A nuclear camera (16) generates associated sets of radiation data spanning both the first and second energy levels from the emitted radiation that is received by solid state detector (20). A means (64) determines associated centers of energy peaks and energy values of the generated data sets. A calibration means (80) calibrates at least one of gain, offset, performance and dead pixel correction based on the determined centers and peaks of the acquired data sets.
摘要:
A new and improved method for calibrating workpiece clamping mechanisms such that once a particular clamping mechanism is calibrated with respect to a particular workpiece to be clamped upon a support surface, the clamping mechanism will always clamp the workpiece with a predetermined, precisely repeatable clamping force. In addition, the method of the present invention may be utilized in conjunction with the calibration of a plurality of clamping mechanisms so as to enable the plurality of clamping mechanisms to always generate the same precise clamping force whereby the multiple clamping mechanisms, utilized to clamp a single workpiece upon a support surface, can in fact clamp different regions of the single workpiece with precisely the same predetermined clamping force such that all regions of the single workpiece are in fact securely clamped.