Development of a New Interferometric Measurement System for Determining the Main Characteristics of Gauge Blocks

A new interferometric measurement system for gauge blocks which does not require wringing onto an auxiliary platen has been developed. The main characteristics of gauge blocks measured in this system are dimensions, coefficients of thermal expansion (CTE) and temporal stability. The repeatability is better than 3 nm for dimensional measurements and a comparison of this system to a conventional one showed good agreement. In CTE measurements, the expanded uncertainty is 3.5 × 10−8 / K. Precision temporal stability measurement is improved since wringing is not required. This interferometer enables better quality control in our gauge block production process.