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Benkova M.,Czech Metrology Institute | Mikulecky I.,Slovak Institute of Metrology
16th International Flow Measurement Conference 2013, FLOMEKO 2013 | Year: 2013

To enlarge calibration capacity of existing liquid flow test bench in CMI - Czech Republic to lower flows a new primary test bench using gravimetric method at atmospheric conditions is being established. The range of flow is (0,001 - 100) mL/min. With accuracy increasing of offered flow meters, of course, requirements to reduce the uncertainty of the primary or secondary standard has been rising. Detailed design of the CMI primary standard equipment and experience with used measuring methods are subject of the article. The main focus of the paper are gap analysis for different dynamic testing methods (weighing, volumetric with piston) as well as detailed uncertainty analysis. Also a traceability chain to the end userś flow meters is presented. Copyright© (2013) by the International Measurement Federation (IMEKO). Source

Yahya A.E.M.,Slovak University of Technology in Bratislava | Halaj M.,Slovak Institute of Metrology
Applied Mechanics and Materials | Year: 2013

Capability indexes of several types belong to the most common tools used for evaluation of the measuring instruments performance over a certain period of time. The indices differ by calculation method, properties as well as by intended use. But their design principle is approximately the same. The ratio of prescribed (required) accuracy and really achieved process accuracy is always observed. However, this evaluation represents only a part of the overall measurements management system. The suitability of capability indexes for the evaluation of CMMs accuracy over a time. After analyzing the results we had found machine capability indexes good method for evaluation of Coordinate Measuring Machines (CMM) accuracy over a certain time interval. CMM are high accuracy and capable to perform the measurement of lengths, machine capability indexes helps to determine the ability for coordinate measuring machine between tolerance limits and engineering specifications, but the use of x-control charts to get and keep processes under control. © (2013) Trans Tech Publications, Switzerland. Source

Svec A.,Slovak Institute of Metrology
Applied Radiation and Isotopes | Year: 2016

Photon energy conversion efficiency coefficient is presented as the ratio of total energy registered in the collected spectrum to the emitted photon energy. This parameter is calculated from the conventional gamma-ray histogram and in principle is not affected by coincidence phenomena. This feature makes it particularly useful for calibration and measurement of radionuclide samples at close geometries. It complements the number of efficiency parameters used in gamma-ray spectrometry and can partly change the view as to how the gamma-ray spectra are displayed and processed. © 2015 Elsevier Ltd. Source

Svec A.,Slovak Institute of Metrology
Applied Radiation and Isotopes | Year: 2015

The paper deals with an alternative model of beta radiation transmissions through attenuation layers and brings another analytical description of this phenomenon. The model is validated with a reliable data set and brings a possibility to calculate characteristic material parameters with low uncertainties. Using no correction factors, these calculations can be considered fundamental and inspiring for further research in the field. © 2015. Source

Zich D.,Comenius University | Zacher T.,Comenius University | Zacher T.,Slovak Institute of Metrology | Darmo J.,Vienna University of Technology | And 3 more authors.
Vibrational Spectroscopy | Year: 2013

Two clay minerals from the kaolin group, namely well-ordered kaolinite and poorly ordered halloysite, were investigated by terahertz time-domain spectroscopy (THz-TDS). Both clay samples were used for preparation of their respective intercalates using dimethyl sulfoxide (DMSO) and potassium acetate (KAc) with water. The intercalates were also characterized by X-ray powder diffraction and Fourier transform infrared spectroscopy. The dielectric behaviour of clay samples was investigated in the far-infrared region of 0.2-2.7 THz corresponding to about 6.7-89.9 cm-1. The frequency dependence of the power absorption coefficient revealed clear absorption bands for DMSO intercalates but not for KAc with water. For kaolinite - DMSO intercalate a distinct doublet at 1.70 THz (56.6 cm-1) and 1.88 THz (62.6 cm -1), and for halloysite - DMSO intercalate a single broad band centred around 1.72 THz (57.3 cm-1) were found. These bands are reported for the first time in this type of intercalation substances and indicate the application potential of THz time-domain spectroscopy for use in the investigation and detection of chemical behaviour of molecular species introduced into the interlayer space of layered substances such as clays and clay minerals. Additionally, the qualitative characteristics of observed bands of DMSO intercalates in the THz region reasonably resembled the structural order/disorder of used kaolinite and halloysite samples. © 2013 Elsevier B.V. Source

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