Dual-range EELS (DualEELS™) is an acquisition mode that allows you to acquire two parts of the electron energy loss spectrum in a fast, sequential manner with independent energy ranges and exposure times. Typically, you use this mode to acquire a core-loss spectrum and the accompanying low-loss spectrum. Hence, it allows you to perform advanced EELS analyses, such as quantification or plural scattering deconvolution.
To acquire dual-range EELS, select Dual in the EELS palette.
Conceptually, the DualEELS acquisition mode is very similar to the Single Range mode, with the addition of a second exposure time and energy offset.
Energy – Specifies the energy loss offset of the low- and high-loss spectra.
Exposure – Indicates the low-loss and high-loss exposures; the sum of these, plus a very small fixed overhead to accommodate the change in state from high- to low-loss, gives the total frame exposure of the camera.
Like EELS mode, the View button starts a continuous dual spectrum view during spectrometer setup and specimen evaluation. During DualEELS mode, it will display both the low- and high-loss live spectra. Once you optimize your parameters, select the Acquire button to capture the DualEELS cumulative spectrum.