Prior to tomography of a work piece, the right imaging scale (magnification) must be selected for the measuring machine. The desired detail resolution must be considered. It must also be ensured that the desired area of the work piece, or the entire work piece, can be fully captured. Raster tomography should be used if necessary.

Magnifications that are used often are set and calibrated at the factory. The user can also calibrate magnifications that are tailored to special tasks. The mechanical axes of the coordinate measuring machine are set up using the joystick, so that the desired image segment is captured on the measured object. The magnification is then calibrated using a standard intended for this purpose, preferably using an automated program. This can be done by measuring calibrated geometric features of the standard itself, or by linearly shifting the standard by measuring the shift of a geometric feature on the standard. After calibration is complete, the quality of the calibration status should be verified by checking the probing error.  The work piece must be suitably fixed on the rotary axis of the measuring machine in order to perform tomography. The work piece fixture should have as little effect on the measurement result as possible. For measured objects made of heavy materials, such as aluminum and steel, plastic work piece fixtures are suitable.  These are much more transparent to X-rays than the metal being measured, and are therefore almost invisible in the radiographic images. If the task is to measure plastic parts, particularly for plastics with little additive content, thin foam plates must be used to ensure sufficient distance between the areas of the work piece to be tomographically scanned and the work piece fixture.  The position of the work piece relative to the rotary axis must not change during the tomography process, because this would cause significant measurement deviations.  Fixing the work piece in foam, which is more temporary, should therefore be avoided if possible. This applies especially if the desired measurement uncertainty is in the range of a few micrometers. In order to minimize the residual measurement deviation when using artifact correction methods, it is often necessary to align the work piece in the same relative position to the X-ray beam path as was used to determine the correction factor.  After positioning the work piece, a few parameters must be set on the measuring machine for the measurement to be performed. By selecting the voltage and current of the X-ray tubes, the image brightness can be changed.