One of the main problems of machining of moulds is the need for an effective monitoring system of wear of cutting tools. This paper presents the results of coordinate measurements of a cutting tool which were obtained by using the non-contact measuring system based on the ACCURA II coordinate measuring machine equipped with the LineScan laser measuring probe and the Calypso metrology software. Investigations were carried out for several measurement strategies including different measurement resolutions and scanning speeds. The results of the coordinate measurements obtained by using the above-mentioned coordinate measuring system were compared to the reference data measured by means of the InfiniteFocus microscope. The measurement results were analysed by means of two software packages: Focus Inspection and Zeiss Reverse Engineering. The point clouds measured by using the LineScan probe were characterized by the selected deviation statistics equal to 4-6 μm when a good match between measurement points and the reference data was obtained. Moreover, these statistics mainly depend on the measurement resolution. The results of the performed experimental research allowed for drawing conclusions concerning the significance of the effect of the adopted measurement strategies on the results of the non-contact coordinate measurements of the selected cutting tool. The application of the non-contact coordinate measurements to the above-mentioned measurement task may contribute to the development of regeneration methods for cutting tools applied for mould manufacturing.
W artykule przedstawiono zagadnienie prawnej kontroli metrologicznej wag nieautomatycznych elektronicznych wprowadzonych do użytkowania na podstawie decyzji zatwierdzenia typu oraz w wyniku dokonania oceny zgodności. Opisano zasadę działania wag nieautomatycznych elektronicznych oraz ich rodzaje. Dodatkowo przedstawiono wymagania jakie, stawiane są wagom nieautomatycznym elektronicznym oraz opisano proces legalizacji ponownej.
EN
The paper presents the issue of legal metrological control of non-automatic electronic scales brought into use based on type approval decision and as a result of assessment of conformity. It describes how non-automatic electronic scales and their types work. In addition, presents the requirements that are placed on the non-automatic electronic scales and describes the process of re-verification.
This paper presents results of two experimental cycles of measurements performed with the use of the terrestrial laser scanner Z+F IMAGER 5006h and the reflectorless tacheometer Leica TPS 1202. These tests aimed at determination of metric properties of surveying instruments, which are used for reflectorless distance measurements and which are often applied to project the geometry of objects. In the course of research works issues influencing the reflection of a laser beam by the measured surface, as well as their influence on the data quality. In order to analyse metric properties of applied instruments, levelling rods were used as test fields of geometrically specified division. It was stated basing on the performed analyses, that the influence of the incidental angle of a laser beam on the accuracy of reflectorless measurements is included within the limits of the error of distance measurements of a given instrument. However, the uniform trend of increasing differences between measured values and the nominal value may be noticed, together with the increase of the incidental angle of the axis of collimation on the measured surface of the test field.
Zaprezentowano metodę w zakresie wyznaczania dokładności wymiarów geometrycznych przemysłowych tomografów komputerowych zgodnie z wytycznymi VDI/VDE 2630. Zaprezentowano propozycje sprawdzenia dokładności tomografu opartą na wzorcu składającym się z zestawu trzpieni z końcówkami kulistymi. Opisano wzorzec zaprojektowany i skonstruowany w Instytucie Metrologii i Inżynierii Biomedycznej Politechniki Warszawskiej. Wzorzec został wykalibrowany za pomocą współrzędnościowej maszyny pomiarowej ACCURA firmy C. Zeiss. Na podstawie uzyskanych danych pomiarowych wykonany został model CAD wzorca. Uzyskane podczas pomiarów tomograficznych chmury punktów zostały porównane z modelem CAD. Przeprowadzono analizę statystyczną uzyskanych wyników oraz sprawdzono podawaną przez producenta dokładność pomiarów geometrycznych tomografu komputerowego METROTOM 800.
EN
This paper presents the construction of a computer tomography scanner (CT). It discusses the principles of operation of CT. The parameters characterizing the accuracy are described. The proposed method for determining the geometric dimension accuracy of industrial computer tomography scanners according to VDI / VDE 2630 is discussed. The presented proposals can be used to verify the tomography scanner accuracy based on gauges consisting of a set of spherical stylus. A gauge to check the CT accuracy was designed and constructed at the Institute of Metrology and Biomedical Engineering, the Warsaw University of Technology. The gauge was calibrated using a coordinate measuring machine ACCURA 7 by C. Zeiss. Based on the measurement data a CAD model of the gauge was made. The measurement strategies were based on the CAD model. The point clouds for tomographic measurements were compared with the CAD model. The results of the two measuring devices were compared. Statistical analysis of the results was conducted. It showed statistically significant differences between the methods of measuring on the confidence level of 95%. It was also confirmed by the statistical parameters obtained for the both methods. The values of the range and standard deviations were approximately twice as high for the tomographic measurements. Also the accuracy specified by the manufacturer of CT METROTOM 800 was verified.
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Po krótkim wstępie zdefiniowano błąd wartości początkowej i błąd przyrostu rezystancji czujnika zmiennej w dużych granicach oraz wyznaczono ich wzory jako funkcje wartości tej rezystancji i przedstawiono przebiegi wartości granicznych tych błędów. Podano wzory miar dokładności rozwarciowego współczynnika przetwarzania prądu na napięcie czteroramiennego mostka rezystancyjnego (4R), tj. wartości bieżące i graniczne jego błędów systematycznych oraz miary średniokwadratowe (dla błędów przypadkowych i niepewności pomiarowych) w przypadku ogólnym i przy tylko dwu lub jednym ramieniu zmiennym. Na podstawie zawartych w normie tolerancji czujników przemysłowych temperatury Pt 100 klasy A i B wyznaczono błędy graniczne mostka z pojedynczym takim czujnikiem dla pomiarów temperatury w zakresie 0-600 oC z uwzględnieniem błędów ramion mostka 4R w kilku przypadkach, tj.: bez regulacji zera, z regulacją zewnętrzną, wewnętrzną i przy pomijalnych błędach początkowych. Podano kilka wniosków, podsumowanie i bibliografię.
EN
Errors of initial value and of increment of broad range variable resistances are introduced. Limited values of these errors are presented. From general formulas of the current to voltage bridge transmittance coefficient, its accuracy measures, i.e. instantaneous and maximum (the worst case) errors and mean square measures (probabilistic errors and uncertainties) for general case and for two or one variable bridge arm are obtained. For given in standard tolerances of industrial Pt 100 temperature sensors of class A and B and given tolerances of arm resistances of the 4R bridge its values of limited errors of full range 0-600 oC temperature measurement in few cases: with external or internal zero adjustment, without it and for negligible initial arm errors, are calculated. Some conclusions, summary and literature are included.
The presented work is a contribution to discussion on usefulness of application of measurement instrumentation used on sea-going ships for energy measurement and scientific research purposes. Contemporary sea-going ships are equipped as a rule with up-to-date measurement instrumentation usually based on electronic data processing and computer technique. These authors have made many times use of such instruments in their research work. This way it was not necessary to install any special instruments, that significantly reduced measurement cost. In such cases to obtain a sufficient accuracy of measurements constitutes a crucial problem. In this paper was presented an analysis of measurement errors of some operational parameters of ship and its main propulsion system, elaborated within the frame of the KBN research project no. 9 T12D 033 17. Results of the analysis confirm usefulness of the standard measurement instrumentation installed on ships, and its sufficient accuracy.
Pokazano próby wytworzenia sygnałów odkształconych w warunkach laboratoryjnych, co pozwoli na pełniejsze badanie urządzeń pomiarowo-zabezpieczających na etapie konstrukcji i badania modeli użytkowych. Badania mają na celu zwiększanie niezawodności, rozszerzanie zakresu funkcji i odporności na zakłócenia elektronicznych systemów pomiarowo-zabezpieczających, pracujących w obiektach energetycznych.
EN
The article presents methods of generation in laboratory of distorted waveforms used in testing of models of protection and measurement instruments. It results in better reliability, performance and higher noise immunity of measurment and protection systems designed for aplication in electrical power engineering.
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