National Repository of Grey Literature 6 records found  Search took 0.00 seconds. 
Determination of measurement uncertainty nano-CMM
Brlica, Pavel ; Jankových, Róbert (referee) ; Šrámek, Jan (advisor)
The topic of this master thesis is the issue of measurement uncertainty of nano-CMM, specifically SIOS NMM-1 machine. Theoretical part of the thesis consists of basic measurement uncertainty definitions, description of approaches to CMM measurement uncertainty and differences between classical CMM and nano-CMM. For measurement uncertainty calculation of nano-CMM, two method are chosen and adapted – substitution method and Monte Carlo method. These are applied in practical part for measurement uncertainty calculation of SIOS NMM-1 machine. Part of the practical part is performed measurement on machine in laboratory at the Czech Metrology institute in Brno. The outcome of this thesis is determination of measurement uncertainty of SIOS NMM-1.
Accurate AC Current Measurements
Nováková Zachovalová, Věra ; Vrabček,, Peter (referee) ; Draxler,, Karel (referee) ; Beneš, Petr (advisor)
In recent years precision measurement of alternating currents goes through large progress especially because of improvements in metrology of electric power, which is related to reduction of electricity consumption. Therefore, more precise measurement of electric energy, power and power quality is required. Measurement range is extending and number of measured frequency points is growing up to 100 kHz. Development of current to voltage transducer with normalized output voltage (0,5 V - 1 V) is in progress because of their easy integration in different measuring systems.. From big area of alternating current metrology this dissertation focuses on development of improved cage shunts for measurement of alternating currents in range 10 mA - 100 A, 10 Hz - 100 kHz. Main objective of this dissertation is to develop theoretical model of existing cage shunts, which will assist design of new improved cage shunts construction. In this dissertation the analytical model of CMI’s cage shunts was established, based on calculating of trans-impedance from cascade matrix of passive two-port which is representing the shunt. Trans-impedance can be used for AC-DC difference and phase error calculation, which are two basic parameters of shunts. Uncertainty analysis of the model was done by means of Monte Carlo method. Next, this dissertation also concentrates on suitable measurement methods of phase error, AC-DC difference, and power a temperature coefficient of resistance. These measurements method were used for calibration of existing CMI’s cage shunts and so the model’s verification was made. Finally, theoretical optimization of existing CMI’s cage shunts constructions and theoretical designs of 20A, 50A and 100A shunts were done using sensitivity analysis results.
Determination Accuracy of Measurement in Nanometrology
Šrámek, Jan ; Číp, Ondřej (referee) ; Tykal, Miroslav (referee) ; Jankových, Róbert (advisor)
The presented doctoral thesis deals with measurements of extremely small sizes in nanometrology using a touch probe, which constitutes a part of a three-coordinate measuring system. It addresses a newly developed method of exact measurements in nanometrology by touch probes. The aim of this work was to expand the measurement options of this device and design a methodology proposal for the measurement of small parts, including the determination of accuracy of measurement of this device when used in nanometrology. The work includes the new methodology for the calculation of uncertainty of measurement, which constitutes a keystone in determining the accuracy of measurement of a accuracy three coordinate measuring system (hereinafter only nano-CMM). The first part of the doctoral thesis analyzes the present situation in the area of evaluation of accuracy of measurement in very accurate length measurements. It defines and describes individual methods implemented in the determination of accuracy of measurement on the instrument nano-CMM. A great emphasis is placed on the methodology of the measurement uncertainty, which draws from the author’s experience as a metrologist working in the laboratories of the Department of Primary nanometrology and technical length, Czech Metrology Institute Brno (hereinafter only CMI Brno). The second part of the doctoral thesis focuses on the determination of accuracy of length measurement in nanometrology, using a large set of measurements that were carried out under the reproducibility and repeatability conditions. There is also described and tested a model procedure utilizing the Monte Carlo method to simulate the measuring system nano-CMM in order to extent the newly created methodology of the measurement of uncertainty using a touch probe on the instrument nano-CMM. A substantial part of this doctoral thesis provides a detailed evaluation of results obtained from experiments that were executed under the repeatability and reproducibility conditions, especially for the purposes of the determination of the uncertainty of measurement. In this doctoral thesis, the uncertainty of measurement is chosen to quantify the accuracy of measurement of the instrument nano-CMM. The final part of this thesis summarizes the knowledge obtained during the scientific research and provides its evaluation. For the methodology used to determine the accuracy of measurement in nanometrology, it also outlines the future development in the area of scientific research, including the practical use in metrological traceability and extremely accurate measurements for customers. Furthermore, it deals with the possible use of other scanning systems compatible with the instrument nano-CMM.
Determination Accuracy of Measurement in Nanometrology
Šrámek, Jan ; Číp, Ondřej (referee) ; Tykal, Miroslav (referee) ; Jankových, Róbert (advisor)
The presented doctoral thesis deals with measurements of extremely small sizes in nanometrology using a touch probe, which constitutes a part of a three-coordinate measuring system. It addresses a newly developed method of exact measurements in nanometrology by touch probes. The aim of this work was to expand the measurement options of this device and design a methodology proposal for the measurement of small parts, including the determination of accuracy of measurement of this device when used in nanometrology. The work includes the new methodology for the calculation of uncertainty of measurement, which constitutes a keystone in determining the accuracy of measurement of a accuracy three coordinate measuring system (hereinafter only nano-CMM). The first part of the doctoral thesis analyzes the present situation in the area of evaluation of accuracy of measurement in very accurate length measurements. It defines and describes individual methods implemented in the determination of accuracy of measurement on the instrument nano-CMM. A great emphasis is placed on the methodology of the measurement uncertainty, which draws from the author’s experience as a metrologist working in the laboratories of the Department of Primary nanometrology and technical length, Czech Metrology Institute Brno (hereinafter only CMI Brno). The second part of the doctoral thesis focuses on the determination of accuracy of length measurement in nanometrology, using a large set of measurements that were carried out under the reproducibility and repeatability conditions. There is also described and tested a model procedure utilizing the Monte Carlo method to simulate the measuring system nano-CMM in order to extent the newly created methodology of the measurement of uncertainty using a touch probe on the instrument nano-CMM. A substantial part of this doctoral thesis provides a detailed evaluation of results obtained from experiments that were executed under the repeatability and reproducibility conditions, especially for the purposes of the determination of the uncertainty of measurement. In this doctoral thesis, the uncertainty of measurement is chosen to quantify the accuracy of measurement of the instrument nano-CMM. The final part of this thesis summarizes the knowledge obtained during the scientific research and provides its evaluation. For the methodology used to determine the accuracy of measurement in nanometrology, it also outlines the future development in the area of scientific research, including the practical use in metrological traceability and extremely accurate measurements for customers. Furthermore, it deals with the possible use of other scanning systems compatible with the instrument nano-CMM.
Determination of measurement uncertainty nano-CMM
Brlica, Pavel ; Jankových, Róbert (referee) ; Šrámek, Jan (advisor)
The topic of this master thesis is the issue of measurement uncertainty of nano-CMM, specifically SIOS NMM-1 machine. Theoretical part of the thesis consists of basic measurement uncertainty definitions, description of approaches to CMM measurement uncertainty and differences between classical CMM and nano-CMM. For measurement uncertainty calculation of nano-CMM, two method are chosen and adapted – substitution method and Monte Carlo method. These are applied in practical part for measurement uncertainty calculation of SIOS NMM-1 machine. Part of the practical part is performed measurement on machine in laboratory at the Czech Metrology institute in Brno. The outcome of this thesis is determination of measurement uncertainty of SIOS NMM-1.
Accurate AC Current Measurements
Nováková Zachovalová, Věra ; Vrabček,, Peter (referee) ; Draxler,, Karel (referee) ; Beneš, Petr (advisor)
In recent years precision measurement of alternating currents goes through large progress especially because of improvements in metrology of electric power, which is related to reduction of electricity consumption. Therefore, more precise measurement of electric energy, power and power quality is required. Measurement range is extending and number of measured frequency points is growing up to 100 kHz. Development of current to voltage transducer with normalized output voltage (0,5 V - 1 V) is in progress because of their easy integration in different measuring systems.. From big area of alternating current metrology this dissertation focuses on development of improved cage shunts for measurement of alternating currents in range 10 mA - 100 A, 10 Hz - 100 kHz. Main objective of this dissertation is to develop theoretical model of existing cage shunts, which will assist design of new improved cage shunts construction. In this dissertation the analytical model of CMI’s cage shunts was established, based on calculating of trans-impedance from cascade matrix of passive two-port which is representing the shunt. Trans-impedance can be used for AC-DC difference and phase error calculation, which are two basic parameters of shunts. Uncertainty analysis of the model was done by means of Monte Carlo method. Next, this dissertation also concentrates on suitable measurement methods of phase error, AC-DC difference, and power a temperature coefficient of resistance. These measurements method were used for calibration of existing CMI’s cage shunts and so the model’s verification was made. Finally, theoretical optimization of existing CMI’s cage shunts constructions and theoretical designs of 20A, 50A and 100A shunts were done using sensitivity analysis results.

Interested in being notified about new results for this query?
Subscribe to the RSS feed.