A contactless, and accurate device and methods of use thereof are provided to calibrate and verify the calibration of a robotic arm and associated attachments. The device uses a laser gauge for calibrating and subsequently verifying the calibration of the robotic arm, digitizer, or robotic tools. An optical transmitter, in communication with an optical receiver is fixed nearly perpendicular to a second optical transmitter in communication with a second optical receiver that form two optical micrometers that are offset a small distance, forming a small gap, d, to create a measuring void having two distinct non-intersecting measurement planes. One measurement plane measures the position and size of an object in a first axis direction and the other measurement plane measures the position and size of an object in a second axis direction. The position and size of an object is measured within the measuring void in both axial directions.