Alignment of irradiated and not irradiated pixel sensors in test-beam operation.

The procedures used to align pixel detectors in test beam operation are presented. Some sensors irradiated up to 10^15 n_eq cm^-2 fluence were operated in partial depletion mode. The effect of a depletion not equal to nominal thickness on the alignment is discussed. An alignment procedure based on the charge collected by the first pixel in clusters has been developed to allow precise measurement of depletion depth.