33results about How to "Improve thickness measurement accuracy" patented technology

A structure and method for polishing a device include oscillating a carrier over an abrasive surface (the carrier bringing a polished surface of the device into contact with the abrasive surface, the oscillating allowing a portion of the polished surface to periodically oscillate off the abrasive surface), optically determining a reflective measure of a plurality of locations of the polished surface as the portion of the device oscillates off the abrasive surface and calculating depths of the locations of the polished surface based of the reflective measure.

Method for measuring thicknesses of a film, a foil or a material layer with a measuring head which is spaced away from the film and with which a capacitive thickness measurement is performed, in which an optical distance measurement is performed with a distance measuring device and a distance determined by the optical distance measurement is used in determining the film thickness in the capacitive thickness measurement.

The invention discloses an ultrasonic detection method of scale thickness in a pipeline. The method comprises the following steps of: utilizing double incidences of ultrasonic waves at different angles, establishing simultaneous equations on the basis of propagation velocities of the known ultrasonic wave on the pipe wall and in the filled fluid and the relationship between an incident angle and a refraction angle of the ultrasonic wave by measuring the penetration time of the ultrasonic waves in the pipeline filled with fluid during the double incidences, and further calculating the velocity and the thickness of a scale layer in the pipeline. With the method, the scale thickness can be measured under the condition that the scale characteristic is unknown, the working detection of the pipeline can be achieved, and the method has reliable accuracy and no destructive effect.

The invention relates to the technical field of laser processing, in particular to a screen plate thickness measurement method. According to the method, the coordinate of a measurement point on a screen plate breadth is (x,y), firstly a laser displacement sensor is moved to the measurement point through shafting motions, measurement is started and thickness data are obtained. The method further includes the following steps: setting a radius r for representing a position range, moving the laser displacement sensor within the position range of the radius r according to a set path, constantly measuring the thickness of the screen plate in the moving process and storing the data until scanning of the laser displacement sensor is completed and the laser displacement sensor returns to the point (x,y), and eventually indicating the thickness of the measurement point with the average value of the obtained thickness data. According to the technical scheme, the thickness of the measured screen plate is obtained, thickness measurement precision of the SMT screen plate is improved, and errors are reduced.

Disclosed is a method for increasing thickness detection precision of a stainless steel cold-rolling mill. The method is characterized by including the steps that steel grade codes and raw material manufacturers are combined to give serial numbers to steel grades, as for different raw material manufacturers which each steel grade corresponds to, corresponding thickness standard plates are respectively manufactured, and the standard plates are used for calibrating a thickness gauge so as to determine alloy compensation coefficients of the steel grades. Thereby, the different raw material manufacturers can be effectively distinguished, and errors of the detection precision of the thickness gauge due to original same steel grade mark but different raw material manufacturers can be avoided. By means of the method for increasing the thickness detection precision of the stainless steel cold-rolling mill, a control system of an existing stainless steel cold-rolling mill is fully utilized, special transformation and added devices are not required, producing requirements can be met, the thickness detection precision can be greatly improved, and the method is simple, practical and reliable.

The invention provides a device for testing the heat conductivity coefficient and the contact thermal resistance of a gas diffusion layer in a compressed state. The device comprises a heating unit, acooling unit, a heat flow column, a heat insulation cover, a temperature measuring unit, an extensometer and a data processing unit; the heating unit comprises a heat insulation cushion block, a heating water tank and a heating constant-temperature water tank; the cooling unit comprises a cooling water tank with a connector at the top and a cooling constant-temperature water tank; the heat flow column comprises an upper heat flow column and a lower heat flow column, the lower end of the upper heat flow column and the upper end of the lower heat flow column are in threaded connection with replaceable test heads, and a test sample is clamped between the replaceable test heads at the upper and lower ends; the heat insulation cover comprises an upper heat insulation cover and a lower heat insulation cover; the temperature measuring unit comprises a plurality of armored thermal resistors and a miniature thermocouple; and the data processing unit is electrically connected with the temperature measuring unit and the extensometer. The device is simple in structure, is combined with a universal testing machine for use, controls the pressure with high precision, and can test the effective heat conductivity coefficient of the gas diffusion layer in a compressed state.

The invention relates to a single-point ring-shaped measuring method for thickness of a surface mounting technology (SMT) screen. The problem that an error is large when the thickness of an SMT screen is measured in an existing laser micromachining industry is solved. The single-point ring-shaped measuring method for the thickness of the SMT screen comprises the steps of setting variable quantity r which represents radius differences of adjacent round rings and setting the number of collected round rings before measurement; if the coordinate of a measuring point M on screen breadth is M (x, y), firstly moving a laser displacement sensor to the position of the measuring point M through axis movement and then moving the laser displacement sensor with a distance r to the positive direction of an x axis, wherein the measuring point is M (x+r, y); collecting reading numbers of the sensor to obtain thickness data; moving the laser displacement sensor with a distance r along the positive direction of the x axis and obtaining the thickness of a circle according to the method; and repeating the steps until the thicknesses of n round rings are obtained. The problem is solved, and the single-point ring-shaped measuring method for the thickness of the SMT screen can be used in the laser micromachining industry.

The invention relates to a thickness and planeness measuring method for a surface mounting technology (SMT) screen. The thickness and planeness measuring method for the SMT screen mainly solves the problems that a screen thickness measuring method is single and can not represent the thickness of a specific area in the prior art. The thickness and planeness measuring method for the SMT screen comprises the steps of using a standard block for calibration to confirm the distance between two sensors, laying the screen flat and moving the two coaxial laser displacement sensors to a starting position of the left lower corner of the screen through axis movement, enabling the laser displacement sensors to move along a certain path to achieve scanning of the whole breadth of the screen, collecting distance information among the upper surface and the lower surface and the sensors, and fitting the obtained distances among the upper surface and the lower surface and the sensors and the obtained coordinates into a thickness distribution picture and a fitting curve picture of the upper surface and the lower surface according to coordinates of points and obtained thickness information after the scanning is finished. The problem is solved, and the thickness and planeness measuring method for the SMT screen can be used in a laser micromachining industry.

The invention discloses a method for measuring the thickness of a boundary layer, and themethod is realized based on a pitot tube moving and measuring device and a double-sided visual ranging system. The method comprises the following steps: installing the pitot tube moving and measuring device at a to-be-measured section of a wind tunnel, wherein the pitot tube moving and measuring device comprises a bracket and a pitot tube fixed on the bracket; marking a plurality of mark points on the surface of the pitot tube in the incoming flow direction; moving the pitot tube moving and measuring device; after each movement, measuring a total pressure value and a static pressure value, and measuring the position of each mark point; according to the position of each mark point before and after movement, obtaining the deformation of the pitot tube under the action of aerodynamic force, correcting the total pressure value and the static pressure value, and obtaining the corrected total pressure value and the corrected static pressure value; calculating to obtain a dimensionless speed of the movement; according to the dimensionless speed of each movement, obtaining dimensionless speed distribution in the boundary layer; and selecting a corresponding movement distance when the dimensionless speed is equal to a preset value, and further obtaining the boundary layer thickness of the to-be-measured section.

The invention discloses an oil film thickness measuring method based on an ultrasonic reflection coefficient real part, and belongs to the field of lubricating state ultrasonic monitoring. The method aims at solving the problem of oil film thickness measurement upper limit of an existing ultrasonic reflection coefficient amplitude method. Firstly, a gap between a friction matrix a and a friction matrix b is an air layer, and ultrasonic reflection signals of an interface between the friction matrix a and the air layer are collected to serve as reference signals; then adding lubricating oil between the friction matrix a and the friction matrix b to form an oil film layer, and collecting an ultrasonic reflection signal of an interface between the friction matrix a and the oil film layer as an oil film reflection signal; respectively carrying out Fourier transform on the reference signal and the oil film reflection signal, and calculating to obtain an oil film layer reflection coefficient; extracting real part information of the reflection coefficient to obtain a reflection coefficient real part; and calculating the thickness of the oil film layer according to the real part of the reflection coefficient and the ultrasonic signal center frequency. According to the method, the upper limit of oil film thickness measurement can be improved by tens of microns, and higher oil film thickness measurement precision is realized.

The invention relates to mica plate sorting, in particular to an automatic mica plate sorting device. The automatic mica plate sorting device comprises a base and further comprises a control unit; a feeding mechanism, a plate taking and conveying mechanism, a measuring mechanism and a material receiving mechanism are arranged on the base, the control unit controls the plate taking and conveying mechanism to take a mica plate from the feeding mechanism, the control unit controls the plate taking and conveying mechanism and the measuring mechanism to measure the thickness of a mica plates, and the control unit controls the plate taking and feeding conveying mechanism and the material receiving mechanism to finish mica plate sorting. According to the automatic mica plate sorting device, the feeding mechanism, the plate taking and conveying mechanism, the measuring mechanism and the material receiving mechanism are controlled through the control center to achieve automatic sorting of the mica plates, automatic measuring and automatic sorting are finished, measuring repetition is good, sorting precision is high, and the sorting interval can be flexibly arranged according to actual needs. Design of four layers of circuit boards is adopted in the control unit, the system stability is improved, a 32 ARM CPU is adopted, and the system processing speed is improved.

The invention discloses a solder paste thickness measuring bracket which comprises at least a sliding rail, wherein two mutually parallel clamping components are slipperily arranged on the sliding rail, and each clamping component is provided with a locking component. The solder paste thickness measuring bracket disclosed by the invention is simple in structure and convenient to use, and can ensure that a double-sided printed circuit board always keeps in a horizontal state in two thickness measuring processes, thereby preventing the double-sided printed circuit board from being affected by a surface mounted component and then improving the thickness measuring accuracy.