|
|
Modification of PCB cleaning process after removing BGA component
Procházka, Adam ; Bžoněk, Tomáš (referee) ; Řezníček, Michal (advisor)
This bachelor thesis deals with the modification of DPS cleaning process after the removal of BGA components. The thesis is divided into five main parts including the introduction and conclusion. The introduction comprises an assignment and aim of the thesis. The first, theoretical, part then deals with different kinds of soldering, individual types of solders and the rework process itself. The second part examines the whole practical part in detail, from the proposal of the test printed circuit board to its mounting, soldering and subsequent testing. Also, it explains the practical tests for connectors. The third part then describes the board testing by thermal cycling. The last part consists of the summary of results, a comparison of individual soldering pastes and conclusion.
|
|
|
Possibility of Measurement Automation
Ilichman, Ondřej ; Košíková, Jana (referee) ; Vdoleček, František (advisor)
The thesis is focused on the automation of measurement with the using of hardware and software. Efforts to objectification processes and eliminating human influence on the outcome are increasingly reflected in the technical fields of measurement. In this work, methods of measurement modification, transformation and subsequent analysis of the measured quantity are discussed. Since nowadays it is possible to automate nearly all types of measurement, it is shown, under what circumstances is appropriate to use automated measurements. The final section is devoted to solution of software and hardware design for measuring temperature in the server room. They are proposed 3 possible solutions and on the basis of their analysis the optimal variant is chosen.
|
|
|
Study of electric properties of composite
Bariš, Marián ; Havlíček, Svatopluk (referee) ; Polsterová, Helena (advisor)
The theme of this Bachelor's thesis is a problematics of composite materials. On a given samples of polyamide with a various weight filling of a milled mica were measured resistivity, permittivity and loss factor on a consequence of a temperature and filling. The chosen type was a filling with a milled mica in range from 0 to 40 of a weight percentage, temperatures were in range from 20 °C to 90 °C.
|
|
|
Expressing uncertainty of measurement
Adamec, Martin ; Vdoleček, František (referee) ; Koška, Petr (advisor)
Master´s thesis is focused on measurement uncertainty problems, particularly on the uncertainty determination and then on the practical application. The thesis is divided into three parts. A theoretical part deals with issues concerning uncertainties on the theoretical level, transition from the measurement error to the measurement uncertainty. This part also clarifies the basic terms concerning this issues based on “ČSN ISO 5168” standard and another legislative materials. The other part is focused on temperature regulations by thermostatic heads and valves. This part also handles thermostatic heads and valves history, division, generally use and legislative background represented by standard „EN 215“. Practical part follows previous sections. I am determining the measure uncertainty of thermostatic heads and valves flow characteristic determining device. All the results and knowledge obtained are given in the conclusion of the thesis.
|
|
| |
|
|
Aggregation reactions of chitosan in drinking water treatment
Leskovjanová, Jana ; Mega, Jaroslav (referee) ; Dolejš, Petr (advisor)
The diploma thesis deals with treatment of surface waters containing humic substances. The most often used method of surface water treatment is coagulation with subsequent separation of aggregates. In this study, only perikinetic coagulation phase was studied. It is the phase when aggregates are formed by the Brownian motion only, i.e. without mixing. Separation of the formed aggregates was made by centrifugation. Coagulation tests were made under the laboratory conditions with model humic water. Humic substances were added from a concentrate, which was taken from a natural peatbog. The influence of temperature on the coagulation process was studied, ranging from 5 to 22 °C. Chitosan (natural biopolymer) was used as coagulant. In present, it is not used in Czech water treatment practice yet. No effect of temperature was observed when chitosan was used as coagulant. Influence of temperature was also studied with the use of aluminium and ferrous sulphates, which are used in common praxis as coagulation reagents. Influence of the temperature was observed and is in agreement with previously reported data of pilot-plant experiments by other researchers. Spectroscopic methods were used to evaluate the coagulation efficiency and determine residual concentration of aluminium and ferrous coagulant. Chemical oxygen demand (COD) was determined for optimal doses. At first, coagulation tests were made under the laboratory temperature. This tests determined optimal aggregation time and optimal coagulant dose under low temperature. Afterwards, all coagulants used were compared at given temperatures.
|
|
| |
|
|
Laboratory thermometer based on Pt100 sensor
Konečný, Jiří ; Murina, Milan (referee) ; Steinbauer, Miloslav (advisor)
This text put mind to questions of touch temperature measurement. Describes the various of electrical temperature sensors, which are divided in accordance with physical principles, on which they work. For each sensor are given its characteristics, such as temperature range, tolerance, advantages and disadvantages, or the measuring circuit. The sensors are described mainly by mathematical equations and polynomials. Their knowledge is needed for the construction of additional circuits or devices for processing information from sensors. In this work is also suggested a completely involvement of digital thermometer, which uses a Pt100. According to this proposal is made a prototype piece.
|
|
|
LabVIEW drivers for resistor decade
Procházka, Matěj ; Čala, Martin (referee) ; Havlíková, Marie (advisor)
This bachelor's thesis deals with description resistance decade M63x and M64x from Meatest company. I described functions and possibilities of remote access. Further are described how it's developed instrument driver in LabVIEW. At the end is cited how I conduct with testing this driver.
|
|
|
Reproducibility and accuracy of polarization mode dispersion measurements
Kováč, Filip ; Brouček,, Jan (referee) ; Šifta, Radim (advisor)
Thesis is divided into two parts. The first part is written rather in theoretical way. It deals with general formation of the dispersion mathematically and verbally. It focuses on the chromatic and polarization mode dispersion. Different types of optical fibers for category G.65X are mentioned as well in connection with the ITU-T. Further attention is drawn first to compensation and then the measurement both of the mentioned dispersions. The thesis describes also analyzers and their main features. The second part is devoted to practical measurements of polarization mode dispersion. In the beginning there are described the components used for construction of the optical measurements and topologies. It is followed by an analysis of an each optical link. The results of these measurement methods and their mutual comparisons are at the end of this section. Measurements in temperature chamber is the subject of a further practical part, which from the beginning captures the essential features of the temperature chamber. This is followed by a description of the measurements, analyses and final valuation depending on the amount of polarization mode dispersion versus the temperature.
|
guest ::
