Fiducialization of the LCLS undulators will be based on magnetic measurements by Hall probe. Pointed magnets, proposed by I.Vasserman[1] for quadrupole lens .ducialization will be used as an intermediate reference. A prototype of the pointed magnet .xture has been made and tested. In this note we will describe a procedure for measuring the position of the center of the Hall probe sensitive area with respect to the undulator .ducial marks. The pointed magnet calibration procedure, a two-point algorithm for locating the magnetic center of the .xture, and test results are presented. Show Partial Abstract