Optical tooling utilizes high power telescopes capable of viewing and measuring small increments over long distances.  Typical instruments include “one-arc-second” theodolites and jig transits to measure angular alignment, straightness and plumb conditions.  Precision leveling scopes are used to measure level conditions.  These instruments do not look directly at the machinery but view specialized ?targeting? fixtures, scales and reflective targets that are set against the machinery components being measured.  In addition, the optical tooling must be properly calibrated and operated by qualified technical personnel who have been trained in specific methods of performing optical alignment work.