A new method to measure the distance between graduation lines on graduated scales

Line scales are used throughout industry for a variety of applications. The most common is the stage micrometer, a small, graduated glass scale for the calibration of optical instruments such as microscopes. However, stage micrometers are generally not calibrated, except for critical applications, due to the time and cost of optical calibration techniques. A method for calibrating line scales is presented which uses electrical test structure metrology. A description of the technique as well as examples of results from this technique are presented.