On the Feasibility of Performing Line Scale Measurments on a High Accuracy Coordinate Measuring Machine

The NIST Linescale interferometer has been used to calibrate line standards for over 50 years. The last substantial upgrade of the instrument was over 20 years ago. The system, which is still very accurate, has become increasingly difficult to support. In this paper we report on a new calibration system being developed for line standards that uses one of the NIST high accuracy M-48 coordinate measuring machine. The talk will discuss the primary limitations of both the M-48 and the linescale, the new line finding microscope, system alignment and measurement process, software control system and data analysis algorithm. Finally performance data on the current version of the system comparing to other systems and algorithms will be presented. System improvements will be discussed at end also.