METROLOGY APPARATUS

摘要

This invention concerns a metrology apparatus comprising a body (110,112) and a first member (118, 116) rotatable relative to the body about a first axis of rotation A3, A4, said first axis being defined by first bearing (120, 128; 122, 129; 124, 130; 126, 132), and a first motor M3, M4 for actuating rotation of the first member relative to the body about the first axis of rotation. A surface sensing device (102) is attachable to the first member such that the surface sensing device can move with the first member, relative to the body. The first motor may comprise a first magnet (152, 158) and at least one metal coil (154) spaced apart along the first axis and mounted such that the first magnet and the at least one metal coil are moveable relative to one another.