2 Things that are needed to pay attention to

Warning: Do not use focused Diffraction spots on CCD! Otherwise, the central spot is so strong that it will damage the Scintillator material that faces electron directly. One may use diffraction mode, as some of people do for their Search mode setup. Just make sure you lower large screen down first before turning on Diff mode and spreading central beam by adjusting the "Focus" knob in Diff mode.

Tip: The CCD should be in retracted position before one inserts the specimen holder into column and before vacuum is ready. So in case of vacuum crash, the back stream oil from ODP pump won't directly drop onto CCD phosphorous surface.

Important: On camera controller, the temperature toggle switch should be at OFF position while P3 is not ready! Normally, the switch is always at "COOL" position to reduce the readout noise. When the vacuum of the scope is not ready, specifically, when P3 is not ready, the camera should not be "COOL"ed or "WARM"ed up for baking. Therefore, one should manually switch to "OFF" position when to vent the camera chamber, or to shutdown the scope.

Note: Obtain gain reference ONLY when CCD is completely cooled down. The final temperature of our system is about -25.3 degree C.