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This paper presents a high resolution measurement set-up developed for calibrating precise line scales with measurement uncertainty of less than 0.1 µm over a total length of 500 mm. The system integrates a numerically controlled multi-axis stage, a laser interferometer, and a vision system for detecting line position. The measurement and the analysis processes are completely automated in order to minimize manual labour during the calibration process, but also increase the calibration accuracy. Increasing calibration accuracy leads up to better quality of industrial measurements which is required by modern precision industry. When designing this set-up, special attention was paid to the alignment of the measurement object in the measurement direction, considering the focus of the camera. The aim of this alignment was to reduce Abbe errors in 2 axes to negligible level. In addition, all uncertainty contributions have been determined and evaluated by performing extended experiments in specific measurement conditions. These contributions are presented in the uncertainty budget. The metrological capabilities of the presented measurement set-up were verified by some practical test measurements. Selected results of these measurements are presented in the article. This set-up will primarily improve a standard base for calibration of optical measuring devices. The use of the optical standards in the industry is constantly growing. Indirect users of the results of this research will be all manufacturers of precise products such as automotive and other industries. [ABSTRACT FROM AUTHOR]

Interlaboratory comparisons are the most powerful tools for determining the competences of laboratories performing calibrations and testing. Performance metrics is based on statistical analysis, which can be very complex in certain cases, especially for testing where transfer standards (samples) are prepared by the pilot laboratory. Statistical quantities are calculated using different kinds of software, from simple Excel applications to universal or specific commercial programmes. In order to ensure proper quality of such calculations, it is very important that all computational links are recognized explicitly and known to be operating correctly. In order to introduce a traceability chain into metrology computation, the European project EMRP NEW 06 TraCIM was agreed between the EC and the European Metrology Association (EURAMET). One of the tasks of the project was also to establish random datasets and validation algorithms for verifying software applications in regard to evaluating interlaboratory comparison results. The statistical backgrounds for resolving this task, and the basic concept of the data generator are presented in this paper. Background normative documents, calculated statistical parameters, boundary conditions for generating reference data sets are described, as well as customer interface. [ABSTRACT FROM AUTHOR]

Tape measures are probably the most wildly used length measuring instruments in the world. The measures, used by surveyors, contractors and other professionals in building and construction industry, measurements of land areas, legal investigations etc. have to be calibrated and for legal purposes verified, to ensure traceability and avoid various controversies, misalignments and other problems. In the paper the precise calibration procedure is presented. In spite of extremely small measurement bench with the length of only three metres, by the use of precise measurement equipment (laser interferometer and video system) and thorough uncertainty evaluation based on experimental and theoretical work, very small calibration uncertainty is achieved. The procedure was successfully accredited and accepted as Calibration and measurement capability (CMC) into key comparison database at BIPM. [ABSTRACT FROM AUTHOR]

Abstract: Mechanical comparison calibration of gauge blocks with dissimilar materials at the highest level is not wide spread because bigger national laboratories tend to calibrate non-steel gauge blocks with reference gauge block of like material. For smaller laboratories this is not viable economically due to the high costs of reference gauge block sets. Therefore, steel reference sets are used for calibrating gauge blocks from other materials. Lack of knowledge about material properties is causing a significant rise in calibration uncertainty. In order to improve best measurement capabilities, we have performed extensive research on gauge block material behaviour. For this purpose we have bought sample gauge blocks from all leading producers and evaluated their influences on the uncertainty budget, based on experimental measurements. The uncertainty budget of gauge blocks with dissimilar materials mechanical calibration, as well as the results of analytical and experimental research, is presented in this paper in detail. Significantly smaller uncertainty of gauge block calibration of dissimilar materials is achieved. [Copyright &y& Elsevier]