Utjecaj zagrijavanja izvora zračenja u računalnoj tomografiji

master's thesis

• Title (english): Influence of X-ray source heating in computed tomography
• Author: Bariša Doko
• Mentor: Marko Katić (mentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2022-12, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering

Abstract

U posljednjih dvadeset godina eksponencijalan je rast i primjena industrijskih CT uređaja u kontroli kvalitete i optimiranju kvalitete proizvoda. Iako je ovo poprilično nova metoda nerazornih ispitivanja, koristi se u raznim sferama strojarstva. Međutim, mjerna nesigurnost ovakvih uređaja još nije potpuno utvrđena i postoje razni utjecaji na točnost mjerenja. Jedan od uzroka je oslobađanje topline pri generiranju X – zračenja i povećanje temperature koje može imati značajne utjecaje na točnost radiograma koji se snimanju na CT uređaju. Za potrebe detaljnijeg prikaza u ovom radu je provedena analiza i mjerenje temperature kućišta izvora X – zračenja i promjena, odnosno pomaka na radiogramima. Ispitivanje je provedeno na četiri razine snage uređaja (10W, 20W, 30W i 40W) te su prikazane ovisnosti temperature o pomacima. Prikazani su grafički prikazi i objašnjenja mjernih podataka sa svih mjerenja, te su podaci povezivani matematičkim i grafičkim modelima u svrhu bolje analize utjecaja temperature na točnost CT uređaja. Dobiveni rezultati pokazuju veliki utjecaj promjene temperature na pomak izvora zračenja, a samim time i pomaka na dobivenim radiogramima. U slučaju dugotrajnijih snimanja, veće su promjene temperature i veći su pomaci. Ispitivanja su pokazala da i razina snage uređaja utječe na promjene i stabilnost rada uređaja.

Abstract (english)

In the last twenty years, the growth and application of industrial CT devices in quality control and product quality optimization has been exponential. Although this is a fairly new method of non-destructive testing, it is used in various spheres of mechanical engineering. However, the measurement uncertainty of such devices has not yet been fully determined and there are various influences on the accuracy of the measurement. One of the causes is the release of heat when generating X - rays is the increase in temperature, which can have significant effects on the accuracy of radiographs recorded on a CT device. For the purpose of a more detailed presentation, this paper analyzes and measures the temperature of the housing of X - ray sources and changes, ie displacements on radiograms. The test was performed at four power levels of the device (10W, 20W, 30W and 40W) and the temperature dependences on the displacements are shown. Graphical representations and explanations of measurement data from all measurements are presented, and the data are connected by mathematical and graphical models for the purpose of better analysis of the influence of temperature on the accuracy of CT devices. The obtained results show a large influence of temperature change on the shift of the radiation source, and thus the shift on the obtained radiograms. In the case of longer recordings, the greater the temperature changes and the greater the shifts. Tests have shown that the power level of the device also affects changes and stability of device operation.

• Keywords: računalna tomografija; CT uređaj; temperatura; dimenzionalna stabilnost; mjerna nesigurnost
• Keywords (english): computed tomography; CT device; temperature; dimensional stability; measurement uncertainty
• Language: croatian
• URN:NBN: urn:nbn:hr:235:391688
• Study programme: Title: Mechanical Engineering; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka strojarstva (magistar/magistra inženjer/inženjerka strojarstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2022-12-01 06:52:33