Capacitive and Incremental Piezo Sensors

In its reference‐class nanopositioners, PI uses capacitive and incremental sensors for non‐contact position measurement. The most important specifications for selecting a suitable method are linearity, resolution (sensitivity), stability, bandwidth and, last but not least, the costs. In addition, it is important that the selected method is capable of directly measuring theplatform motion, allowing the controller to detect any position change of the platform, relative to the base body. This makes it possible to achieve accuracies in the sub‐nanometer range.