|Speciale, Modul 3. modul, 2008, id:261|
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The goal was to develop an experimental method that could measure the thermal expansion coefficient independent of any local field assumptions. We have chosen a capacitative method of determining the thermal expansion and measuring the dielectric constant of a viscous liquid near the glass transistion. Our measurements show a response that can be considered to be caused by thermal expansion of the liquid, but due to instability of the sample holder the magnitude of the hermal expansion coefficient can not be trusted. The response measured by our dilatometric method is qualitatively in agreement with the dielectric method proposed by Bauer et al. [2000a,b]. We believe that the dilatometric method used is sensible, and with som adjustments to the equipment, it can be brought to an adequate level of precision to produce a quantitative measure of the thermal expansion coefficient, independent of any local field assumptions. Although, this does depend on the disappearance of a yet undetermined effect, that we believe causes the sample holder expansion to alter when the capacitor is filled with liquid, as opposed to being empty.