20.500.12556/RUL-186882 Vpliv uravnoteženosti Wheatstonovega mostiča na merjenje magnetostrikcije The influence of Wheatstone bridge balance on magnetostriction measurement V zaključni nalogi je bilo obravnavano merjenje magnetostrikcije z uporovnimi lističi v kombinaciji z Wheatstonovim mostičem. Meritve so potekale na sistemu za merjenje fizikalnih lastnosti (Physical Property Measurement System -- PPMS), ki omogoča merjenje v magnetnem polju od $-9\,\mathrm{T}$ do $9\,\mathrm{T}$. Glavni cilj naloge je bil razvoj testnega merilnega instrumenta, ki omogoča hkratno merjenje štirih vzorcev, kar je v primerjavi z merjenjem enega samega vzorca časovno ugodnejše. Metoda je tudi cenovno ugodna, saj so upori in uporovni lističi za izdelavo štirih Wheatstonovih mostičev poceni. Prednost takšnega načina merjenja je tudi v tem, da so upori, vezani v Wheatstonov mostič, izven kriostata, zato so med merjenjem ves čas pri enakih pogojih. V sklopu naloge so bila analizirana tudi odstopanja uporov in uporovnih lističev od nazivnih vrednosti ter njihov vpliv na meritev in rezultate. Na koncu so bile izvedene še testne meritve za aluminij in neorientirano elektropločevino, pri temperaturi $T = 300\,\mathrm{K}$ in v magnetnem polju od $-9\,\mathrm{T}$ do $9\,\mathrm{T}$. This thesis addresses the measurement of magnetostriction using strain gauges in combination with a Wheatstone bridge. The measurements were carried out on a Physical Property Measurement System (PPMS), which enables measurements in a magnetic field ranging from $-9\,\mathrm{T}$ to $9\,\mathrm{T}$. The main objective of the thesis was to develop a test measurement instrument capable of measuring four samples simultaneously, which is more time-efficient than measuring a single sample. The method is also cost-effective, as the resistors and strain gauges required to build four Wheatstone bridges are inexpensive. A further advantage of this measurement approach is that the resistors connected in the Wheatstone bridge are outside the cryostat, so they remain under constant conditions throughout the measurement. As part of the thesis, the deviations of the resistors and strain gauges from their nominal values were also analysed, along with their effect on the measurement and the results. Finally, test measurements were performed on aluminium and non-oriented electrical steel at a temperature of $T = 300\,\mathrm{K}$ and in a magnetic field ranging from $-9\,\mathrm{T}$ to $9\,\mathrm{T}$. magnetostrikcija Wheatstonov mostič PPMS magnetostriction Wheatstone bridge PPMS true false false Slovenski jezik Angleški jezik Zaključna naloga 2026-09-06 08:15:38 2026-09-06 08:15:44 2026-09-08 13:09:33 0000-00-00 00:00:00 2026 0 0 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 162693 290371843 23908.pdf 23908.pdf 1 3449E390020167B956FC0893E90C7CE5 0dbd65ca6de94d2bd7712bc04e6081e01bc2cbbbb82419ff576184bde3d8e8a6 62f4280f-a9ba-11f1-8bc5-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=246264 Fakulteta za matematiko in fiziko 0 0 0