An apparatus for measuring a surface of a workpiece is described. The apparatus comprises a support, attachable to the moveable arm of a machine, such as a coordinate positioning machine, and rotatable about first and second axes of rotation, the axes driven by first and second motors respectively. The apparatus additionally comprises a surface sensing device for sensing the surface of a workpiece, rotatable about a third axis of rotation. This third axis of rotation is alignable with the first axis of rotation, and when aligned, rotation of the support relative to the surface sensing device is actuatable by the first motor. A method for using an apparatus for measuring a surface of a workpiece is also described.