HADES is a versatile magnetic spectrometer aimed at studying dielectron production in pion, proton and heavy-ion induced collisions. Its main features include a ring imaging gas Cherenkov detector for electron-hadron discrimination, a tracking system consisting of a set of 6 superconducting coils producing a toroidal field and drift chambers and a multiplicity and electron trigger array for additional electron-hadron discrimination and event characterization. A two-stage trigger system enhances events containing electrons. The physics program is focused on the investigation of hadron properties in nuclei and in the hot and dense hadronic matter. The detector system is characterized by an 85 % azimuthal coverage over a polar angle interval from 18• to 85• , a single electron efficiency of 50 % and a vector meson mass resolution of 2.5 %. Identification of pions, kaons and protons is achieved combining time-of-flight and energy loss measurements over a large momentum range. This paper describes the main features and the performance of the detector system.

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The presented article focuses on measurements of extremely small dimensions in nanometrology using tactile probes. It addresses a newly developed method of precise measurements in nanometrology by touch probes, where the measurements are carried out on the machine SIOS NMM-1. The aim of this work is to determine accuracy of measurements on this machine. The main contribution of this work is a creation of a methodology for the measurement of precision parts and determination of accuracy of measurement when using this device in nanometrology. The work also includes methodology for the calculation of measurement uncertainty, a keystone in determining the accuracy of measurement in nanometrology. The article provides results of representative sets of measurements of ruby ball diameters, including the evaluation of statistical parameters and determination of the combined measurement uncertainty.

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The present article deals with the measurement methods based on experimental tests and their impact on the resultant volumetric error of CNC machine tools (MT). Volumetric error compensations represent a promising technology to increase the production accuracy of machine tools. This article studies direct and indirect methods to measure the volumetric accuracy on a MT. The assessed parameters are not only the resultant volumetric error of the machine, but also time consumption of measurement, repeatability, and evaluation of individual geometric errors. Finally, recommendations are made to improve the effect of volumetric errors compensation using the above-mentioned methods for three-axis MT.