Development of the New Line Scale Calibration Facility at the Dutch National Metrology Institute VSL

摘要

Line scales are important physical standards of length used for accurate positioning or measurement in one, two or three dimensions. Depending on the application, line scales can have dimensions from fractions of a millimeter to several tens of meters. For example, small scales are used to calibrate the field of view of optical microscopes. Scales with dimensions in the meter range are used to read out the position of machine tools and measuring machines, while leveling rods find their use in geodetic surveying. Accurate calibration of scales requires dedicated equipment and measurement conditions that are usually only implemented at the national metrology institutes. The Dutch National Metrology Institute VSL (formerly NMi Van Swinden Laboratorium) has several facilities to calibrate scales from small micrometer scales up to leveling rods and tape measures with lengths over tens of meters to high accuracy. In order to ensure that we can continue to provide services for the ever increasing demand for higher accuracies, these facilities are continuously improved. This paper will describe the efforts that have been undertaken recently to improve our capabilities for the calibration of high precision line scales as well as the motivation for the choices that have been made during this process.