The Advanced Interference Detection Array (Aida)
In principle, interference detection is unlimited in respect to concentration: differences in concentration within the measurement cell cause a fringe shift in the interferogram, proportional to the concentration increment dc at any concentration.
In practice, this unlimited application will fail at very low and very high concentrations. At low concentrations, noise will become dominant, not allowing to isolate the signal. At high concentrations, the fringe gradients will become too steep to be resolved. Such interferograms cannot be transformed into usable data.
Both limitations can be overcome by increasing the surface size of the detector, which is simply a CCD camera. This is the basic enhancement realized by Aida, supplemented with improvements to the periscope and optics. Thus, the applicable concentration range has been extended to 0.05 to 150 g/L – in combination with long (20 mm) and short (1.5 mm) measurement cells.
Aida has been developed by Nanolytics in order to provide service measurements on the Analytical Ultracentrifuge with the best data quality available. It will be serviced and further developed by Nanolytics Instruments in the future. It is not generally intended for sale, but may be distributed to institutions that guarantee to apply Aida for their own research only and to ensure that Aida will not be handed on to other AUC service facilities.