An articulated measuring head for orienting a probe relatively to a measuring apparatus, including: a support element; a first mobile element rotatably connected to said support element and capable of turning around a first rotation axis relative to said support; a plurality of mobile positioning elements united with said first mobile element; a plurality of fixed positioning elements united with said support element and capable of engaging with said mobile positioning elements to define a plurality of predetermined orientations of said first mobile element relatively to said fixed element, said fixed positioning elements being essentially arranged in a positioning plane; an automatic actuator capable of being in a locked state and in an unlocked state, arranged to exert an unlocking force onto said first mobile element to move said first mobile element away from said support element and allow the rotation around said first axis when said actuator is in the unlocked state; and a locking force on said first mobile element to tighten said first mobile element against the support element and prevent the rotation around said first axis when said actuator is in the locked state; a first encoder arranged to determine an angular position of said first mobile element relative to said support element; one rotation actuator for turning said first mobile element relative to said support; an electronic control unit for controlling said rotation actuator dependent from outputs of said first encoder; a first bearing and a second bearing for guiding said first mobile element relative to said support element, the first bearing being closer to the positioning plane than the second bearing, the second bearing having a higher play than the first bearing. a support element; a first mobile element rotatably connected to said support element and capable of turning around a first rotation axis relative to said support; a plurality of mobile positioning elements united with said first mobile element; a plurality of fixed positioning elements united with said support element and capable of engaging with said mobile positioning elements to define a plurality of predetermined orientations of said first mobile element relatively to said fixed element, said fixed positioning elements being essentially arranged in a positioning plane; an automatic actuator capable of being in a locked state and in an unlocked state, arranged to exert an unlocking force onto said first mobile element to move said first mobile element away from said support element and allow the rotation around said first axis when said actuator is in the unlocked state; and a locking force on said first mobile element to tighten said first mobile element against the support element and prevent the rotation around said first axis when said actuator is in the locked state; a first encoder arranged to determine an angular position of said first mobile element relative to said support element; one rotation actuator for turning said first mobile element relative to said support; an electronic control unit for controlling said rotation actuator dependent from outputs of said first encoder; a first bearing and a second bearing for guiding said first mobile element relative to said support element, the first bearing being closer to the positioning plane than the second bearing, the second bearing having a higher play than the first bearing.