9762 papers found
According to the progress of industrial products, high-accuracy and minute parts are increasing rapidly. As one of the desired measuring systems for accurately and efficiently evaluating the 3D form of these mass-production minute form parts, an evaluation system constructed by combining "a high-accuracy stage", "minute probes" and "an optical unit" is described.
In the article, the form deviation (roundness) measurement with the Coordinate Measuring Machine has been discussed. The influence of the measuring points number and the type of the roundness deviation on the result (since different fitting elements are used) has been presented. The obtained investigation results prove that minimal number of points is not enough for measurement, while the too large number does not improve the measurement, as well. The recommendation on the measuring points number have been given.
This paper demonstrates the application of the ISO GUM for analysis of the measurement processes used in the product control. It describes the attention in the method application and the need to establish the acceptability criterion for the measurement process. But also their advantages, such as, the identification of the existent uncertainty sources, the simplification through the sample selection and the application of a confidence level of 95,45%.
National Metrology Institute of Japan studied the high precision angle indexing table. We used the principle that NPL reported the indexing accuracy 0.01" in 1984. We verified this principle using the angular primary standard of Japan and proved this principle can exceed 0.001" super-high angular precision.
The main purpose of this study is to develop a measuring device by parallel kinematics for measuring a motion accuracy of multi-axis machining centers. The initially developed measuring device had three displacement sensors and it could measure only position of the spindle because it had only 3 DOF. Optical linear encoders were used for the displacement detecting sensors, while the steel balls and permanent magnets were used for the joints of parallel mechanism. With the 3 DOF device the motion accuracy of machine tools with three-axis was measured. Since the mechanism of the joint was...
Metrology practice confirms that very often by carrying out the corrections the result of measurement may contain greater error (deviation) than in the case of no corrections at all. Therefore, it is often assumed that the value of correction is zero, with assumed influences on the uncertainty of correction included in the uncertainty of the measuring results. In the field of length metrology the correction cannot be avoided in case of temperature influences or actions of the measuring force during the measurement procedure. Numerous experiences show that temperature correction is a...
A technique for the out of machine calibration of analog probes for CMM is presented in this paper. The process and the results obtained in different tests carried out on two different probes are shown. This calibration procedure allows to find out the measuring errors of these systems in a quick and reliable way.
Inline-metrology is an important aspect in actual production concepts. The philosophy is to gain measurement data directly in the manufacturing processes and use them for an effective and fast process control and quality assurance. The goal is to increase the quality of products and the stability of processes.
In practice, ninety percent of the engineering faults initiate from the surfaces by means of the mechanisms of fatigue crack wear behavior, corrosion and erosion. In this point of view, researchers are attracted by measuring surface and near-surface zone suitability of work pieces and evaluation studies. Surface roughness is a factor not only in composing the work piece aspect but also in defining the performance of the work pieces in coating processes. In this study, 3 different test specimens are subjected to molten glass that was in forming temperature and the changing surface roughness...
Practical use of Machine Vision for surface roughness estimation faces many challenges, as in this case only image is used for evaluation and not the component. In such cases, if the component is kept at an angle during imaging, there is a possibility of getting distorted information and therefore the consistency of evaluation/ quantification would become a problem. So, there is a need to ensure that the measured surface is kept horizontal and flat when the image is being taken. In this work, estimation of the surface roughness has been done and analysed using digital images of machined...