|
|
Failure analysis based on measurement of vibrometric data
Jánoš, Vít ; Klusáček, Stanislav (referee) ; Šedivá, Soňa (advisor)
This paper deals with the analysis of vibration data from a screw compressor. A single axis piezoelectric sensor is used for the measurements. Within the scope of this work, a software is developed to retrieve the measured data through REST API and perform further processing such as frequency spectrum analysis, envelope analysis or signal cepstrum calculation. An algorithm to compute a fast kurtogram has also been implemented. Kurtogram is used for determination of demodulation band prior to envelope analysis The measured data and the indicators from the analyses are stored in a database.
|
|
| |
|
|
Automation of the calibration process
Mařas, Michael ; Šedivá, Soňa (referee) ; Beneš, Petr (advisor)
This master thesis deals with the automation of the calibration process at the workplace for calibration of electronic power meters and the description of the method of evaluation of calibration results. The paper analyses the calibration workstation and the manual method of calibration performed by the calibration laboratory staff. Furthermore, proposals for automating the manual method of calibration and a description of the implementation of a program for automating this process are given. Subsequently, the uncertainty analysis is described in the paper. In this section, the uncertainty analysis according to the GUM method and the subsequent calculation of these uncertainties are presented. The correctness of the calculation of uncertainties according to the GUM method is verified by the Monte Carlo method. In the last part of the work, the method of evaluation of the calibration results according to ILAC-G8:09/2019 is described and the form of the calibration protocol is described.
|
|
|
Measurements of small flow rates
Lorenc, Dominik ; Šedivá, Soňa (referee) ; Mancl, Vlastimil (advisor)
The thesis deals with the extension of the laboratory fixtures with a~measuring track designed for the measurement of small fluid flows, on which the thermal flowmeter is tested. The used calibration methods are examined and the track is then subsequently constructed. A~measurement operating program is also developed to set the measurement parameters and to store the measurement data in the required format. The parameters and characteristics of the reference scale used and the thermal flowmeter provided are then measured on the constructed track. The measurement results are presented and the uncertainties of the selected flow rates are determined.
|
|
|
Noise control of needle bearings
Štetinová, Iveta ; Krejčí, Jakub (referee) ; Šedivá, Soňa (advisor)
The bachelor thesis deals with the noise of needle bearings. By analysing the noise of the bearings, it is possible to find out the technical condition of the bearing and reveal the types of bearing damage. The beginning of the work is devoted to the theory of bearing noise. Vibration diagnosis methods are described. In the practical part, a manual noise meter is tested, and the investigated values are evaluated by a system for measuring the noise of bearings. The primary objective of this thesis is to find out how the noise of the bearings could be controlled more effectively.
|
|
|
Diagnosis of metallic materials
Buday, Matej ; Šedivá, Soňa (referee) ; Bejček, Ludvík (advisor)
This thesis deals with non-destructive testing (NDT). It Describes two basic thermographic methods, lock-in and pulse thermography. Different types of measurements using Fluke Ti55, points to the possibility of applying these methods in practice. Pulse thermography issue is a substantial part of this work, due to its good applicability. Also, it compares visual testing methods (VIS) and pulse thermography due to measurement with die-casting alloy AC-AlSi9Cu3 (Fe).
|
|
|
Algorithm for leakage detection
Kratochvíl, Adam ; Šedivá, Soňa (referee) ; Pikula, Stanislav (advisor)
The thesis deals with the presentation of an overview of the methods used for leak detection set by technical standards. Following the analysis of the pressure records from the pipeline, a new method is proposed, which is based on existing methods and uses the determination of the direction of arrival of the wave directly at the measurement station. The proposed concept was subsequently developed in Matlab, where the ability to detect was also verified. The whole algorithm was then implemented in programmable logic controllers and a suitable communication between them was designed. The entire solution was then tested in terms of functionality.
|
|
|
Uncertainty Calculation by the Monte Carlo Method
Kósa, Valentin ; Šedivá, Soňa (referee) ; Havlíková, Marie (advisor)
This bachelor’s diploma thesis deals with the measurement inaccuracies. Various types of uncertainty, methods, their specifications and ways of their recording are described. Next, Monte Carlo method and its application are introduced to the reader. Next, both methods described are applied: calculation of accuracy using uncertainty – GUM method and calculation of accuracy using Monte Carlo method. The methods are applied in measurements of DC current at resistive load with different meters.
|
|
|
Reliability of Technical Systems
Jirgl, Miroslav ; Šedivá, Soňa (referee) ; Havlíková, Marie (advisor)
This thesis deals with a reliability of technical systems. It is divided into four main parts. The first part deals with the mathematical description of reliability. Probability and statistics are used for this description. This part includes the definition and properties of random events, the description of discrete and continuous random variable and its distribution. The second part contains the definition and expression of reliability, types of faults in the digital circuits and the reliability of electronic components. This part introduces into problems of reliability. The third part includes making the reliability diagrams and reliability analysis. Each method is briefly described here. Further advantages and disadvantages of using each method are given here. The two most widely used reliability analysis - Failure Mode and Effect Analysis - FMEA (resp. FMECA) and Fault Tree Analysis – FTA are described in a greater detail. The last part focuses on an example of calculation of reliability. An analyzed object is Universal Charger NiMH and NiCd batteries. Reliability is analysed by block diagram, FTA and FMEA.
|
|
|
Thermal conductivity measurements
Herr, Tomáš ; Šedivá, Soňa (referee) ; Beneš, Petr (advisor)
This bachelor thesis is focused on measurement of thermal conductivity and description of measurement principles by different methods. These methods are divided into stationary, unsteady, with linear sources and with point sources. Partially is this thesis dedicated to the research of the market with devices measuring thermal conductivity, other part is creating an overview of Czech national norms. The practical part is dedicated to an experiment proposal, realization of measurement itself and final validation of results. The principle of the experiment is based on non-stationary measurement made by line-linear source which is working on pulse mode.
|
guest ::
