A national traceability in force measurement to the Regional Reference Standards Laboratory (Department of Legal Metrology) without much degradation in the uncertainty while transferring the unit from the National standards to the user is achieved by developing and commissioning a dead weight force machine of 50 kN capacity at Regional Reference Standards Laboratory (RRSL), Bangalore and 50 kN comparator type force machines at other (RRSLs located at different parts of India. The established standard machines are directly compared for their performance through an artifact calibrated against...
A method for comparing pressures of different mediums generated by gas and hydraulic pressure balances is examined to improve consistency between gas and hydraulic pressure-standards. The pressure range compared is 0.5 MPa to 7 MPa. In the method, a liquid-lubricated pressure balance was used and a precise pressure transducer was applied as a comparator to determine the equilibrium state between the two pressure balances. In this paper, the comparative result and the uncertainty obtained from the method are presented. From the results, it was shown that the method adopted in this study could...
A fast infrared scanner is used to acquire the thermoelastic effect induced temperature changes along a line on the surface of cyclically loaded tensile samples. The raster scanning movement of the single detector allows the sampling of temperature versus time. This data are then post-processed by means of a lock-in algorithm coupled with 1D and 2D FFT analyses in order to filter out the thermoelastic signal from the noisy measured signal. A data extension algorithm is proposed which uses the information from different acquired frames to extend the data sampling window. The whole signal...
The article presents the importance of the EDM technology in the industry of machine building. It is mostly used in the machining of stamps and special processes in which the conventional technologies are inefficiently. It's known that only condition of machining with this method is that the material should be electro conductive. The main parameters that are followed during the process are the precision and the roughness of the surface. The collective tried to emphasise the importance variation of the roughness concerning some machining parameters. Some of the measurements were conducted at...
The estimation of the fixed-point temperatures T ph from measured plateau curves can be carried out using different mathematical methods. Depending on the method used and the size of the fixed-point cell, different systematic deviations and reproducibilities of the calculated temperatures arise. They typically develop during the evaluation of measurements from small fixed-point cells. Thus the phase transformation temperatures of miniaturised fixed-point cells with zinc of different purities were measured and five different methods were compared.
Among mobile systems which are being implemented more generally to the measuring practice such as coordinate measuring arms (CMA), there is a lack not only commonly accepted methods of accuracy assessment but also procedures to determine the accuracy of any realized measurement, what is particularly important and expected by industry. According to the authors application of simulation using virtual CMA would be the effective solution. In this article the model of kinematic, metrological CMA elaborated in Laboratory of Coordinate Metrology in Cracow University of Technology and its research...
A minimal wearable system to monitoring remotely normal free-living activity (e.g. laying, sitting, standing, and slow walking) of patients in their home space is proposed. Owing to its wireless features, the system can represent a useful tool to be implemented in a long-time patient monitoring system. These systems are useful for the clinical out coming or for minor chronic pathologies not requiring hospitalization.
Density measurements are frequently associated to specific requirements in order to evaluate the quality of a process or to determine mass and/or volume of the material. Hydrostatic weighing is the usual method to get directly the traceability to the SI system of the density as well as of the solid volume. INRIM (the former CNR - IMGC) supplied to IPQ a hydrostatic apparatus with a measuring cell, devoted to measure the density of liquids and the volume (density) of small solid bodies, with technical support and assistance in the density field. Since 2005 the partnership between the two...
Gas sensors based on surface acoustic wave transducer equipped with two types of primary electronic circuit, oscillatory circuit and a circuit of phase shift detection, are described. Modal character of oscillatory circuit is analyzed, and consequence of this fact are discussed. Results of investigations for this type of circuit are presented. A conception of SAW transducer with phase shift detection is proposed, a simple electronic circuit for this method is described and results of investigations are presented.
Both, the ISO-GUM and the Supplement S1 of the GUM require expressing the knowledge about the measurement process by a so-called measurement function, which represents the mathematical relationship between the relevant parameters, the influence quantities, and the measurand(s). Nevertheless, both documents are confined to lumped-parameter systems in the steady state. Since dynamic measuring systems gain more and more importance, modern uncertainty determination must develop appropriate modelling approaches for dealing with dynamic measurements. This paper exemplarily describes a possible...