Calibration

KappaCCD User Manual

Revision 1.10, Last Update 1-July-1998

Calibration

Calibration comes in several flavors. Calibratable items are for instance distortion, sensitivity, camera orientation and position, and dark current. Of all these calibrations, only camera orientation and position can be calibrated on site and should be repeated when the X-ray tube is changed or other alignment work is done.

Calibration procedure after alignment.

Collect a standard data set on the test crystal.

Data collection parameters

Position:
Theta=0
Phi=0
Omega=160
Kappa=0
Dx=25

Scan:
25 seconds
90 frames
repeat=1, delta phi=2

Do NOT use the factory dataset provided with the system!
Calibration has to be done with a locally collected data set in order to describe camera settings after final installation.

Start Denzo-SMN and load the Initial.set file.
Make sure the menu fields are reflecting the datacollection setup parameters.
Use 20 frames for peak searching.
Use a 3D-window of 30 frames.
Refine all parameters until no further shifts occur. Leave the refinement window visible
Reload the Initial.set file.
Take the following values from the refinement window and place them in the corresponding fields of the Site card.

Refinement window output

Cassette RotX
Cassette RotY
(Cassette RotZ remains zero)
Xbeam
Ybeam
Crossfire X
Crossfire Y
Crossfire XY

User Interface Site Card

Rotation X
Rotation Y
Rotation Z (=0)
Beam Position X
Beam Position Y
Crossfire X
Crossfire Y
Crossfire XY

Save the values in the Initial.set file through the File menu

Test the calibration

You can test the calibration by loading the new Initial.set file and index again the same data set. Successful calibration will yield very low Figures of Merit in your indexing table. Back