Calibration of rotary tables can be performed using autocollimators or laser interferometer systems. In this investigation a comparison between these two methods of calibration as applied on an optical rotary table has been carried out. The calibrated table is a Carl Zeiss optical rotary table of resolution 30 arcsecond. An Elcomat® 3000 autocollimator system and an Agilent® 5529A laser interferometer system have been used in this calibration. A precise indexing table of 360 serrations with accuracy of ± 0.5 arcsecond manufactured by Davis® and a glass polygon of 12 faces with accuracy of ± 0.3 arcsecond delivered by MOLLER WEDEL GmbH has been used. The indexing table is used in co-operation with the laser system while both of the polygon and the indexing table are used with autocollimator system. Repeated results from the different methods of calibration were carried out and presented in the paper. Uncertainties associated with the measurement results for each method have been estimated using the procedures mentioned in GUM. The paper discusses the accuracies as well as difficults and ease associated with each method.

In this contribution we present an approach toincremental interferometric measurements of displacements over a limited range where the atmospheric wavelength of the coherent laser source is either directly stabilized to a mechanical reference or is corrected to fit to the reference. The idea comes from the possibility to use a highly stable material for a reference frame, material which can perform thermal expansion coefficients on the level 10^-8/K within a large temperature range up to 50K. Over a range of several K which may be the practical range for displacement measurements the coefficient is even smaller. This may outperform the best techniques of correction for the variations of the refractive index of air. The mechanics is always a part of the measurement setup and represents one of the sources of uncertainty. A link of the refractive to the mechanical reference can practically eliminate another source of uncertainty.

We present the results of far-field nanoscopic investigation on the sub-micrometer localization and characterization of defects in optoelectronic devices (e.g. monocrystalline silicon solar cell structure) due to the material processing. Solar cells are generally prepared from Si-ingots sawed into thin round wafers by metallic wire. Hence, first defects appear on the sites of metallic precipitates, which reduce quantum efficiency of cells. Second type of defects then originates from further fitting of the round wafer into square cells. The latter can be dimensioning by mechanical sawing or breaking, laser opening or water jet stream cutting. Laser opening, as one of new processing techniques which could diminish the losses in the cells, is a promising tool but not yet well developed. Therefore this paper brings first results of preliminary study concerning the influence of laser cutting on the behavior of semiconductor p-n junction.

Surveying instruments have to meet certain specifications in order to provide the necessary accuracy standards for a certain application. The main purpose of testing a used terrestrial laser scanner (TLS) is does an instrument still meets factory accuracy standards or not. This paper outlines the procedures for the investigation of the TLS accuracy in laboratory conditions without high expensive equipment e.g. a calibration track line and a laser interferometer. The test field contains control targets and observation pillars. 3D position of the pillars and the targets are derived from an adjustment of highly precise measurements and they are considered asa true standard compared with the scanned data. A proper statistical model of the data analysis is proposed. In addition to the theoretic model, a particular sample of the highly precise TLS measurements is analyzed.

Combining contact and non-contact CMM probes provides a promising solution to meet the increasing requirements on complexity and accuracy of dimensional metrology, and benefit inspection performance. However, the automated planning of measurement strategies for such hybrid CMM systems hasn’t been well addressed yet. This paper proposes an automated inspection planning approach for CMM inspection combining tactile probing and laser scanning. The right sensor is first selected for each feature being inspected. According to the selected sensor, the suitable procedures are performed to create the inspect plan automatically. Experiments are carried out to verify the developed approach.