See what you measure !

Most dielectric spectroscopy systems are blind. Apart from the information given in the dielectric data, you know little about the actual state of your sample. When doing research on novel materials it may be very difficult to understand what is going on in the sample from the dielectric data alone. This is why we incorporated an automatic texture monitoring facility in Sigma, giving you microscopy photos of your sample at any stage of the experiment.

With your sample in a microscope equipped with a video camera (Sigma presently supports standard USB webcams as well as the National Instruments PCI-1411 framegrabber card; more options are under development), you can have the texture photographed continuously during the dielectric measurement or at any particular stage of the experiment, for instance after reaching a new temperature, applying a new DC-bias, after the dielectric scan is over etc.

The automatic texture monitoring feature is particularly useful when measuring anisotropic samples, e.g. liquid crystals, polymers or composites. You get a verification of the sample orientation (or of the orientation and / or distribution of filler components in case of composites) throughout the measurement and you can directly correlate events in the dielectric spectrum with changes in the texture, signifying for instance a phase transition, filler aggregation, dielectric breakdown or alignment change.

Here you can download a research paper where the power of combined dielectric spectroscopy and texture monitoring is demonstrated for the case of liquid crystal research.