|Speciale, 3. modul, 2007, id:240|
|Vejleder:||Niels Boye Olsen|
|Findes på RUb:||Ja|
This report presents a new experimental technique based on an alternative use of the piezoelectric bulk transducer used at IMFUFA/NSM, RUC. The measurements rely on the pyroelectric effect of the piezoceramic material that compose the spherical hollow tranducer shell. In order to explain and analyze the experimental test results, an analytic model is proposed as a solution to the thermo-electro-mechanical differential equations describing the phenomena in the transducer and what fills the cavity inside. Measurements involving the highly viscous 5-PPE / Santovac 5 liquid are conducted in the temperature range from 248 K to 260 K near the supposed glass transition of the liquid, during which a drastic change in the physical thermodynamic variables is documented for the liquid. The practical test measurements and the theoretical thermo-electro-mechnical equations are compared for a discussion of the potential of the experimental technique and possible improvements before its application in experimental glass physics are proposed; it is concluded that the technique may be an excellent method for measuring the isobaric thermal expansivity, (formel), but at present it needs complementing experiments to decrease the number of independent variables. The report is written in English.