Prepare a gain reference
- First set up even illumination on the detector.
- Ensure that the transmission electron microscope (TEM) is in Imaging mode, with no sample features in the spectrometer field of view.
- For dedicated spectrometers:
- Go to the EELS Acquisition floating window.
- Set the dispersion to 0.0 eV/ch.
- Start energy to 0 eV.
- Set the aperture size to the minimum size.
- Open the EELS Acquisition Setup Options dialog and choose a camera mode with 1x1 binning and Show 2D image checked.
- Select View in the EELS Acquisition dialog, with exposure set to 0.1 s; the intensity in the spectrum 2D view should be centered, if not adjust the Start Energy until the beam is centered.
- With the spectrum view still running, increase the entrance aperture until the whole detector is completely illuminated.
- Adjust the beam on the TEM to attain a count level of about 1/3 the saturation limit (21,000 for 16-bit detectors), and leave the system viewing for about 2 – 5 minutes to "anneal" the scintillator.
- Stop the spectrum view.
- Go to the EELS Acquisition floating window.
- For imaging filters:
- Ensure the spectrometer is in Unfiltered imaging mode.
- Start a camera preview with 4x binning, 0.125 s for GIF Quantum® series (HQ mode, 0.0160 s for GIF Continuum® systems) and adjust the beam to ensure even illumination on the detector.
- The image intensity should be approximately 20,000 counts (GIF Quantum) or 350 counts (GIF Continuum) at this binning and exposure. If not, try changing the spot size or emitter settings.
- Stop the camera preview.
- In the Camera menu, select Prepare Gain Reference to make sure the Target Intensity and Frames to Average are set to
Prepare a gain reference.- GIF 2000 and earlier Gatan imaging filter (GIF) users – 8,000 and 10, respectively
- Enfina, GIF Tridiem®, GIF Quantum, and Enfinum™ users – 21,000 and 10, respectively
- GIF Continuum, Continuum S users – default dose rate, typical operating exposure, and gain reference exposure factor are recommended.
- Target dose rate for gain reference is 250 – 351.
- Follow any on-screen prompts during the automated gain reference acquisition procedure.

