DualEELS results in effortlessly measure precise energy shifts and apply advanced quantification routines for a new level of EELS analysis. It allows the operator to acquire two optimized EELS spectra from different energy ranges (e.g. one low-loss and one core-loss) in rapid succession. The hardware includes a beam deflector used to deflect the beam from the different acquisitions in different subregions in the EELS CCD.

The high-speed 2 kV Spectrum Offset Module provides a precision energy offsets of up to 2 keV and switching times in the order of 10 μs. It requires an additional electronics. This module pushes high-speed DualEELS to the maximum readout rate of the detector while adding minimal overhead. In static applications, the 2 kV range of the module allows hysteresis free energy offsets beyond the Si-K edge enabling accurate core level shifts to be measured for all the elements in the periodic table. In DualEELS mode, the maximum ΔE in energy with the standard drift tube is 1,000 eV from the start of the first spectrum to the start of the second spectrum. However, the maximum ΔE with the fast drift tube 963.U4 is 2,000 eV.