Apparatus and method for assessing the beam profile of a non-contact tool setting apparatus

A method for assessing a beam profile of a light beam of a non-contact tool setting apparatus, the non-contact tool setting apparatus comprising a transmitter for emitting the light beam and a receiver for receiving the light beam, the receiver generating a beam intensity signal describing the intensity of received light, the non-contact tool setting apparatus being mounted to a machine tool having a spindle that is moveable relative to the non-contact tool setting apparatus, the method comprising the steps of:

• (i) loading an object having an edge into the spindle of the machine tool, and
• (ii) using the machine tool to move the spindle relative to the non-contact tool setting apparatus so that the edge of the object passes through the light beam;
• (iii) determining the beam profile of the light beam using the beam intensity signal generated at a plurality of positions of the light beam relative to the edge during the step (ii) of moving the edge of the object through the light beam;
• and
• (iv) performing a tool measurement operation to measure a position of a part of a tool carried in the spindle of the machine tool,
• wherein the beam profile determined in step (iii) comprises a value indicative of the beam width.