Temperature-dependent electrical resistivity
For several years the electrical properties of different composites filled with nanotubes have been investigated under different objectives. To a large extent, films are produced and their conductivity is measured as a function of the percentage of fill and the arrangement of the nanotubes both along the film and through the film. Especially the contacting of the foils plays an important role. In the past, several measuring adapters for different test object shapes were built and tested. Based on the experience gained with these measuring adapters, a new measuring adapter was designed, which allows not only defined contact conditions but also heating of the test object. With the help of an electronic unit, which contains the heating control and a logic circuit, and a newly developed software it is possible to carry out automatic measuring processes on a test object. These measuring sequences allow the measurement of the resistance of the sample in different directions while simultaneously running through a freely programmable temperature step program. This makes it possible to determine the resistance and conductivity in different directions of the film without changing the position of the test object and without manual wiring changes.
Construction: Mathias Ullrich, IPF
Electronics production: LWS Mess- und Labortechnik GmbH Radeburg
Temperature controller: JUMO dTRON 308
Measuring module: DT9812 from Data Translation
Software: Agilent VEE Applikation