3. Sensor calibration

A detector must be calibrated for gain and offset (black image), at the factory of course, but also in the clinic at regular intervals. Imperfect calibration can be very visible on the screen, depending on the state of the detector: its temperature can vary on the scale of a few minutes (affecting the quality of the black image), its ageing becomes noticeable on the scale of a few years (altering the gain), and so on. The two calibration families use distinct methods.