RESUMEN
In this article, we propose a method for improving accuracy in calibrating Leeb hardness testers using fiber interferometric systems. The calibration system is implemented using the photonic Doppler velocimetry technique. This paper provides estimates of the measurement uncertainty arising in the calibration system and describes a method for improving accuracy, which takes into account the signal-to-noise ratio, sampling rate, and processing parameters.
RESUMEN
A three-coordinate heterodyne laser interferometer has been developed to measure the displacement of the probe microscope scanner with a subnanometer resolution that provides traceability of measurements to the standard of meter through the wavelength of a stabilized He-Ne laser. Main sources of errors are investigated, and their influence is minimized so that the resulting measurement uncertainty of the system does not exceed 0.2 nm, and the resolution is 0.01 nm. The investigation of metrological characteristics of the three-coordinate interferometer was carried out with a scanning probe microscopy (SPM) NanoScan-3D using TGZ-type calibration gratings. The values measured with SPM fell within the 95% confidence interval given by Physikalisch-Technische Bundesanstalt (PTB) (Germany). SPM equipped with a laser interferometer was used to measure the characteristics of dynamic etalons of geometric dimensions.
