Novocontrol Instruments

Coaxial line reflectometry has to be employed at frequencies from 1 MHz to -1 GHz. In contrast to the low-frequency techniques already described, here the sample capacitor is used as the termination of a low-loss precision coaxial line. The complex reflection factor is measured with a microwave reflectometer at the analyzer end of the fine, depending on the sample impedance. For this purpose, the incoming and reflected waves are separated with two directional couplers and their amplitudes are measured. The BDS concept 70 is a commercially available system (Novocontrol Instruments) that uses the coaxial line reflectometry method. This system covers the frequency range between IMHz and 3 GHz with loss factor tan 5 resolution of less than 3 x 10 . The... 

Novocontrol, ALFA Series Analyzers, http //www.novocontrol.de/html/index analyzer.htm. Zahner, Electrochemical Workstation IM6, http //www.zahner.de/download/b im6.pdf Gamry Instruments, Reference 600 PotentiostatlGalvanostat, Operator s Manual, 2012. 

Aspects of common DEA techniques are presented in the following paragraphs, with emphasis on the instrumentation that is likely to be used in a typical thermal analysis laboratory examples are Novocontrol Spectrometers (BDS), TA Instruments (DEA 2970, although the production of this instrument has been discontinued), and Polymer Laboratories (DETA, this instrument is not available any more either). Dielectrometers (Micromet Instruments, now owned by Netzsch), used for in-process cure monitoring of thermosets, operate on similar principles. Features of the sensitive thermally stimulated current technique, and its comparison to DEA, are also discussed. 

Sample Preparation and Dielectric Spectroscopy Measurements. Dielectric relaxation spectra were collected using a Novocontrol GmbH Concept 40 broadband dielectric spectrometer over the frequency range 0.01 Hz - 3 MHz and over the temperature range of 0 to 100° C. The temperature stability of the instrument was controlled to within 0.2° C. 

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