A substrate processing system includes an optical measurement assembly coupled to an exterior of a processing chamber that has a portion that is transparent. The processing chamber includes a reference object and a pedestal for supporting a work piece. The optical measurement assembly measures a lateral location, a height and a tilt of the pedestal by transmitting light into the processing chamber through the transparent portion of the processing chamber and detecting a reflected light from both the reference object and the portion of the pedestal after the reflected light leaves the chamber through the transparent portion of the processing chamber. A method of adjusting a pedestal includes analyzing the reflected light and leveling the pedestal, translating the pedestal, calibrating the pedestal height to a preheat ring level, and checking the level and location of the pedestal in response to the analyzed reflected light.