Materials Science Forum, Vol.505-507, 379-384, 2006
Abbe error-free test equipment for nanometer-order measurements
In order to ensure manufacturing quality, precise measuring instruments and sensors play an important role for the accurate measurement of products. For length measurements with submicrometer precision, the nano gauging displacement transducers (NGDT) have been often utilized. NGDT can achieve a resolution in the nanometer order and an accuracy of less than 100 nm. To guarantee the accuracy and the traceability to the definition of the meter, calibration and test of NGDT are necessary. The current methods and machines suffer from various disadvantages. Some of them allows only manual test procedures and some automatic tests can reach only uncertainties of more than 100 run. To realize an automatized and accurate test of NGDT, a test equipment was developed, that with a resolution of 1.24 nm, a measuring range up to 20 mm and a measuring uncertainty of approximate 10 run can fulfil the test requirements. The main problem for realization of this test system is minimization of the Abbe error which is a first order error and will result in a significant error. For reaching this goal an angular control system and piezo translators are applied. With the aid of a measuring program adhering to the measurement principle outlined in VDI/VDE 2617 guidelines, an automatic test less than thirty minutes was realized. By theoretical and experimental investigations it can be shown that the automatic test equipment achieves a test uncertainty of approximate 10 rim corresponding to a relative uncertainty of approximate +/- 5(.)10(-7). With small uncertainty and short test time, this test system with an Abbe error-free stage is available for the accurate test of high precision gauging displacement transducers.