Abstract: Unique circuit location sensing apparatus for component placement robots (100) utilizes a high-resolution optical reflective sensor (110) for detecting the location of selected circuit runners (300, 301) on a printed circuit board (350). The sensor (110) is mounted to the robot arm (106) and coupled by A/D converting circuitry (104) to the robot computer (102). The robot computer (102) positions sensor (110) over a selected runner (300, 301) and steps sensor (110) across the selected runner (300, 301), storing the digitized sensor output for each step. The robot computer (102) processes the digitized sensor outputs to determine the actual location of the selected runner (300, 301) and then calculates location offsets for the component placement program to be subsequently run on the robot computer (102). As a result, variations in actual location of circuitry on different printed circuit boards (350) are automatically compensated for and components are more accurately placed thereon.