Optical Measuring Machine

Keywords Dimensional metrology Uncertainty calculus Monte Carlo method Optical Measuring Machine. 

Conceptually an optical measuring machine can be divided into two subsystems, a "machine system" and an "optical system". The "machine system" consists of a monoblock structure holding the measuring table and allows the displacement of the axes. The "optical system" consists of a charged-coupled device (CCD) which allows the acquisition and transfer of images to a computer connected to the "machine system" as well as the necessary lenses and objectives to obtain images of a given resolution. The system made up of CCD camera replaced the "contact sensor system" used in a CMM. This subdivision allows us to analyze separately the two systems in order to achieve a model as a basis for the evaluation of uncertainty. 

Image Acquisition. The image obtained by the optical measuring machine, which is represented in matrix form as ,]) is transformed to gray scale. 

GOM (2008) Application example quality control, sheet metal measuring characteristic features using the optical measuring machine TRITOPCMM. GOM mbH, Rev. A (en) 03042008, http //www.gom.com/fileadmin/user upload/industries/tritop cmm EN.pdf... 

In addition to the building parameters, there are often some requirements from suppliers of processes and equipment to make sure their parts function properly. This may mean that the requirements for the equipment decide the target levels (e.g., in pharmaceutical and electronics industries). In other cases there are restrictions on deviations from the target levels (e.g., on temperature for machine control system or on humidity and vibration for optical measure nient systems). ... 

For a superior introduction to this difficult topic, try Peter Rock s now classic book, Chemical Thermodynamics, Oxford University Press, Oxford, 1983. The treatment in Temperature Measurement (second edition), by Ludwik Michalski, Joseph McGhee, Krystyna Eckersdorf and Jacek Kucharski, Wiley, New York, 2001, is aimed at engineers manufacturing temperature-measuring machines, such as electrical and optical sensors, but some of its introductory material might help. 

A sophisticated optical sorting machine will track the average colour of the product so that, even though the average product colour may change with time, the machine will continue to remove only the predefined abnormal particles. Optical sorting machines are often provided with a white calibration plate which is either manually or automatically placed in the optical view at user-defined intervals. The machine is then able to correct for any measurement drift that has occurred. 

The measuring methods used, for example to monitor O-rings, include optical CNC machines, mechanical scanning systems and plug gauges. 

The digital optical measurement systems have achieved wide spread in recent years in industry, reaching a share of around 20 % of the world market. These systems present interesting advantages over the coordinate measuring machines (CMM) with probing mechanical methods, mainly the speed of data acquisition, automation of measurement functions and, above all, the absence of contact. 

P. Maresca, E. Gomez, J. Caja, C. Barajas, M. Berzal, Use of coordinate measuring machines and digital optical machines for the geometric characterization of circumference arcs using the minimum zone method. Measurement 43 (2010) 822-836. 

A.C. Majarena, J. Santolaria, D. Samper, J.J. Aguilar, Modelling and Calibration of Parallel Mechanisms using Linear Optical Sensors and a Coordinate Measuring Machine, Measurement Science and Technology, 22 (2011) 105101-1-12. 

Precision techniques are required to measure the finished products, including CNC coordinate measuring machine (CMM) capability with associated CAD/CAM features, laser micrometers, form-scan geometry gauge, optical comparators, and other digital gauges. 

Local effects like necking lead to local strains and strain-rates broadly differing from the global values that are measured by the machine itself Optical measuring systems based on digital image correlation, however, allow the examination of the local deformations and thus the determination of the local strains. Additionally the actual cross section of the specimen can be detected. Combined with the global force the actual, local stress can be determined. This results in a much more accurate determination of the mechanical material properties, especially about material failure. 

Two-dimensional measurements for the geometrical characterization of the shape of the weld lines. Position and orientation of the weld lines have been investigated by means of an optical CMM (Coordinate Measuring Machine). 

In this research work, the weld lines of a micro injection molded component were analyzed. In particular 00 A statistically designed experiment has been carried out molding plastic micro components. Different process parameter settings were investigated in order to determine their influence on the weld lines, oo Weld lines were quantitative characterized both in the two-dimensional (direction and position in the X,Y plane) and three-dimensional range (Z-depth determination). For this purpose an optical coordinate measuring machine and an atomic force microscope have been used respectively. 

Tables 4—6 Ust ASTM methods used for the characterization of PB and PMP. A number of specialized methods were developed for testing particular articles manufactured from polyolefins several of these determine the performance of PB and PMP film, including the measurement of the film s dart impact strength and tear strength. Dart impact strength is measured by dropping a heavy dart with a round tip on a stretched film. Tear resistance, which reflects the film s resistance to tear propagation, is measured with the Ehnendorf tear tester. Two values for the tear strength are usually reported, one in the machine dkection of the film and the other in the transverse dkection. Pipes manufactured from PB are tested by pressurizing them internally with water the time-to-burst failure is determined at various temperatures (46). The standard test method for haze and luminous transmittance (ASTM D1003) is used for the measurement of PMP optical characteristics.

Basically, the optical method uses equipment such as alignment telescopes, jig transits, and sight levels. Instruments with built-in optical micrometers for measuring displacements from a referenced line of sight enable an accurate determination of target movements, which are mounted on the machine. 

For intermediate temperatures from 400-1000°C (Fig. 11), the volatilization of carbon atoms by energetic plasma ions becomes important. As seen in the upper curve of Fig. 11, helium does not have a chemical erosion component of its sputter yield. In currently operating machines the two major contributors to chemical erosion are the ions of hydrogen and oxygen. The typical chemical species which evolve from the surface, as measured by residual gas analysis [37] and optical emission [38], are hydrocarbons, carbon monoxide, and carbon dioxide. 

While the dial-indicator and optical methods differ in the equipment and/or equipment setup used to align machine components, the theory on which they are based is essentially identical. Each method measures the offset and angularity of the shafts of movable components in reference to a pre-selected stationary component. Each assumes that the stationary unit is properly installed and that good mounting, shimming, and bolting techniques are used on all machine components. 

As a major branch of nanotribology. Thin Film Lubrication (TFL) has drawn great concerns. The lubricant him of TFL, which exists in ultra precision instruments or machines, usually ranges from a few to tens of nanometres thick under the condition of point or line contacts with heavy load, high temperature, low speed, and low viscosity lubricant. One of the problems of TFL study is to measure the him thickness quickly and accurately. The optical method for measuring the lubricant him thickness has been widely used for many years. Goher and Cameron [3] successfully used the technique of interferometry to measure elastohydrody-namic lubrication him in the range from 100 nm to 1 /rm in 1967. Now the optical interference method and Frustrated Total Reflection (FTR) technique can measure the him thickness of nm order. 

An apparatus for measuring the dynamic modulus and hysteresis of elastomers. The stress-strain oscillogram is shown on a ground-glass screen by means of an optical system. Now superseded by modem computer controlled servo hydraulic and dynamic mechanical thermal analysis machines. Roll Bending... 

There is great interest in the electrical and optical properties of materials confined within small particles known as nanoparticles. These are materials made up of clusters (of atoms or molecules) that are small enough to have material properties very different from the bulk. Most of the atoms or molecules are near the surface and have different environments from those in the interior—indeed, the properties vary with the nanoparticle s actual size. These are key players in what is hoped to be the nanoscience revolution. There is still very active work to learn how to make nanoscale particles of defined size and composition, to measure their properties, and to understand how their special properties depend on particle size. One vision of this revolution includes the possibility of making tiny machines that can imitate many of the processes we see in single-cell organisms, that possess much of the information content of biological systems, and that have the ability to form tiny computer components and enable the design of much faster computers. However, like truisms of the past, nanoparticles are such an unknown area of chemical materials that predictions of their possible uses will evolve and expand rapidly in the future. 

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