33results about How to "Large calibration range" patented technology

The invention discloses a single-end SAR ADC capacitance mismatch calibration method, which can calibrate the error caused by the capacitance mismatch of the SAR ADC. This method only needs to insert two pairs of redundant capacitors in the analog domain, and compensates for capacitance mismatch in the digital domain. The binary capacitor DAC containing two pairs of redundant point capacitors includes the segmented binary capacitor DAC and the redundant capacitors Cjr+, Cjr- inserted in the lowest bit Cj of the segmented capacitor MSB segment, and the redundant capacitors Cqr+, Cqr+ inserted in the LSB segment Cqr‑. The redundant bit calculation module adds the inserted redundant bit and other normal bits to calculate an effective output of N-bit. The capacitance mismatch calibration module performs capacitance mismatch compensation on the output result. This calibration method only adds two pairs of redundant capacitors to the traditional SAR ADC structure, and the calculation of mismatch compensation is performed in the digital domain, thereby reducing the layout area and the complexity of the analog circuit.

The invention discloses a magnification factor calibration method for a microscope. The magnification factor calibration method comprises the following steps of: with a standard raster with a known raster pitch as a reference, acquiring a raster image in a microscope to be calibrated; carrying out fast Fourier transform on the acquired image to obtain a spatial frequency spectrum; selecting an interval where certain level of resonant frequency is located from the spatial frequency spectrum, and carrying out local high-resolution discrete Fourier transform to obtain a local high-resolution spatial frequency spectrum; selecting a frequency with a maximum amplitude as a resonant frequency from the local high-resolution spatial frequency spectrum, and dividing the resonant frequency by the level to obtain a base frequency; calculating the size of the standard raster corresponding to the image by using the raster pitch and the base frequency; and calculating the magnification factor of the microscope by using a ratio of the display size of the image to the size of the standard raster corresponding to the image. Compared with the traditional method, the magnification factor calibration method is high in precision, large in calibration range and wide in applicability when being used for calibrating the magnification factor of the microscope.

The present invention provides gas calibration method for semiconductor equipment. After certain amount of gas is introduced through mass flowmeter to closed chamber, the pressure change before and after gas introduction is measured and inside gas mass change is calculated based on the gas state equation, so as to judge whether the mass flowmeter has normal operation. Compared with available technology, the present invention has the advantages of wide calibration range, fast calibration, low cost and excellent calibration effect.

The invention relates to a method for calibrating misalignment angles of a two-dimensional autocollimator. The method comprises the following steps: (1) rotating azimuth angles and pitch angles of a reflecting mirror to determine pixel numbers, azimuth angles and pitch angles (x, y, h, v) in the horizontal direction and the vertical direction corresponding to m*n points; performing fitting on the m*n points by using multiple curved surfaces to obtain corresponding coefficient matrixes of the azimuth angles and pitch angles, and for any point in an imaging region, resolving the azimuth angle and the pitch angle of the point according to the pixel numbers x and y in the horizontal direction and the vertical direction of the point and the coefficient matrix of the azimuth angle and the pitch angle. The method provided by the invention is flexible to use, the fit maximum number of times and the number of measuring points can be continuously changed according to a calibration result until the requirement on the calibration accuracy is met, and moreover, the higher the fitting times is, the more the measuring points are, and the higher the calibration accuracy is.

The invention provides a device for calibrating space charge density measurement equipment, and the device comprises a power supply, an upper electrode plate, a lower electrode plate, insulating supporting columns, an arc light lamp, a galvanometer, a platform, and a fan. The positive and negative electrodes of the power supply are respectively connected with the lower and upper electrode plates through wires, and the lower and upper electrode plates are supported by the insulating supporting columns. The galvanometer is disposed on a wire between the negative electrode of the power supply and the upper electrode plate. The arc light lamp is disposed at the edge of the lower electrode plate, and the fan is located above the arc light lamp. The platform of the space charge density measurement equipment is placed between the upper electrode plate and the lower electrode plate. The device is clear in principle, is simple in structure, is low in manufacture cost, is safe and convenient for use, is large in calibration range, and is suitable for the calibration of different types of space charge density measurement equipment. The device is mainly used for the calibration of the space charge density measurement equipment based on an ion counting method, a Faraday cage method, a charge screening method and a probe array method.

The invention relates to a photoelectric response characteristic calibration method for a two-dimensional imaging device, which comprises a ray diffraction grating, a focusing optical system, a two-dimensional imaging device to be calibrated and a computer system, wherein an incident light beam for calibrating the two-dimensional imaging device is a light beam parallel to the plane, the light beam is imaged on the photosensitive surface of the two-dimensional imaging device after being modulated by the space intensity of the ray diffraction grating and being converged by the focusing optical system, the incident light beam forms a series of diffraction sub light spots with modulated light intensity on the photosensitive surface of the two-dimensional imaging device through the beam splitting characteristic of the ray diffraction grating, a plurality of groups of measured data are fused through peak value measuring data of each diffraction sub light spot and peak value theoretical dataobtained by theoretical calculation, the measured data and the corresponding theoretical data are obtained, the two groups of data are combined for completing the photoelectric response characteristic calibration of the two-dimensional imaging device. The photoelectric response characteristic calibration method has high light energy utilization rate, is applicable to the photoelectric response characteristic calibration of the two-dimensional imaging device under the condition with strong light sources and is also applicable to weak light sources, and the calibration range is enlarged throughthe fusion of a plurality of groups of measured data.

The invention belongs to the technical field of optical fiber measurement, and particularly relates to a calibration device for optical coherence polarization measurement and a dynamic range calibration method thereof. The device comprises a broadband optical source and power monitoring device 510, a first optical fiber connector 521, a second optical fiber connector 522, a high-precision calibration device 530, an optical path correlator 540, and a polarization crosstalk detection and signal recording device 550. A polarization-maintaining optical fiber with a specific length and an alignment angle is used for building a calibration device, and the position and the magnitude of a measurement peak are precisely positioned; by using two-order interference peaks of multiple crosstalk points, a low peak value is precisely positioned; and by using different calibration gradients, the calibration precision and the accuracy are improved.

The invention relates to the technical field of meter calibration, and discloses a computer aided calibration method for a coal flow meter in the shell coal gasification process, which includes: acquiring production information related to a coal circulation phase online to automatically divide coal circulation load intervals and automatically search stable flow intervals; estimating reliability of data of the stable intervals; and finally giving linear regression, quadratic regression and cubic regression functions according to the calibration requirement, and giving a selection standard for regression ways. The computer aided calibration method can be used for effectively avoiding errors occurring in manual reading and calculation in calibration of a traditional coal flow meter, improving flexibility of data processing, and increasing calibration speed and improving calibration precision evidently.

The invention relates to a space pose calibration method of a high-precision laser beam of a non-orthogonal shafting laser total station. The method comprises the following steps of constructing a calibration device by adopting a two-dimensional turntable with high precision and a hemispherical target, keeping the hemispherical target in a camera view field, and fixing the hemispherical target ona target seat on an optical platform so that a sphere center of the hemispherical target is superposed with the sphere center of a reflective hollow target sphere; acquiring a three-dimensional coordinate of a first position of the hemispherical target in a world coordinate system; randomly moving the hemispherical target to obtain the three-dimensional coordinate of a second position in the worldcoordinate system; repeating operation till that world coordinates of the hemispherical targets at n positions in a space and pitching and horizontal angles corresponding to the precise two-dimensional turntable; carrying out quaternion rotation reverse calculation on the coordinates of fixed points on laser beams from the second position to an nth position to obtain the coordinate at an initialposition; and using a least square method to carry out fitting and obtaining a space pose of the laser beam.

The invention discloses a vidicon calibrating method based on double one dimensional drones; the method includes the following steps: two freely arranged one dimensional drones are set; the images of the drones are shot from different angles through a vidicon; vidicon coordinate systems and image plane coordinate systems of the vidicon under different shooting positions as well as a world coordinate system are respectively built; internal parameters and external parameters of the vidicon are solved after carrying out aberrance calibrating on the shot drone images. The calibrating method of the invention takes two one dimensional drones as a calibrating object, carries out shooting on the drone images from different angles after freely arranging two one dimensional drones on the field area of the vidicon and can carry out calibrating on the internal parameters and the external parameters of the vidicon only after picking up three or more characteristic points of each drone image; auxiliary devices are not needed; the vidicon calibrating method based on double one dimensional drones of the invention is simple to operate, and can improve the calibrating precision of the vidicon and enlarge the calibrating range of the vidicon.