Z. Krajicek, D. Prazak, J. Tesar, M. Vicar, T. Hajduk
Standardization of negative gauge pressures is a peripheral branch of pressure metrology, but this approach is unfair. Although this pressure mode can be ensured simply by liquid columns, the utilization of pressure balances in this area brings many technically interesting solutions. They include an inverse piston-cylinder design (it is the basis of most commercial solutions), a classical pressure balance with generation of negative gauge pressure under a bell jar, a digital piston manometer and a pressure divider designed for absolute pressure mode. The paper focuses on the methods utilized...
Cultivating Metrological Knowledge
· TC16
· 2007
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S. Zuñiga-Gonzalez, P. Olvera-Arana, J. C. Torres-Guzman, F. J. Flores-Martinez Oral Presentation (Pressure)
With the purpose to establish deviations and concordance levels for negative pressure measurements in Mexico, and by a request from the Mexican Accreditation Body (ema), the pressure and vacuum group in CENAM (the Mexican National Metrology Institute) organized a proficiency test among laboratories from the National System of Calibrations (SNC). In this proficiency test most of the Mexican secondary laboratories with the capabilities to perform calibrations in this measurement range participated. This document presents the results and the concordance level obtained among the laboratories...
Cultivating Metrological Knowledge
· TC16
· 2007
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P. Olvera-Arana, J. C. Torres-Guzman, A. Navarro-Nateras, J. Aranzolo-Suárez
At the end of 2006, the Pressure Group of the Centro Nacional de Metrología CENAM, Mexican National Metrology Institute, organized and piloted a proficiency test in hydraulic gauge pressure in the range from 7 MPa to 70 MPa for accredited laboratories by the Entidad Mexicana de Acreditación (ema), Mexican Accreditation Body. For the proficiency test, the pilot laboratory (CENAM) carried out three calibrations of the transfer standard; the first one at the beginning of the proficiency test, the second at the middle and the last one at the end of the program. With the measurements made by...
Cultivating Metrological Knowledge
· TC16
· 2007
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C. Villarroel-Poblete, J. C. Torres-Guzman, P. Averlant, A. Knott, R. Kumme, J. A. Robles-Carbonell, D. Ramirez-Ahedo, L. R. Giobergia
A force comparison was carried out among various laboratories from Euromet and SIM, in order to estimate the level of agreement for the realization of the quantity and the uncertainty associated to its measurement. The comparison was carried out in two ranges one at 1 kN and the other at 50 kN. In order to achieve best accuracy of the force transducers the measurement range started at 40% of the maximum transducer range. The results obtained, the deviations graphs that include the uncertainty for each laboratory are presented in this document.
Cultivating Metrological Knowledge
· TC3
· 2007
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C. Marinari, J. C. Torres-Guzman, A. Germak, D. A. Ramirez-Ahedo
The present paper describes the results of the bilateral comparison carried out between the CENAM (Mexico) 150 kN force standard machine and the INRiM (Italy) 1 MN Force standard machine. The two dead weight machines, their main metrological characteristics and the procedures of the comparison are described. Three different load cells (50 kN, 100 kN and 200 kN capacity) were used as transfer standards, and the test was made at 2 different load levels and at 5 angular positions for each load cell. The main results of the comparison with the relevant uncertainties from the measurements carried...
Cultivating Metrological Knowledge
· TC3
· 2007
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C. Morales-Aguillon, J. C. Torres-Guzman, D. A. Ramírez-Ahedo
The Mexican National Metrology Center (CENAM) has installed a Dead Weights Force Standard Machine as national standard with a measuring range up to 153.6 kN (MMS-150 kN), which allows to carry out calibrations of force transducers in traction or compression mode. This machine has an automatic system which permits, by a series of comparisons with well known masses, to perform a calibration procedure in three different modes (high accuracy, low accuracy and special procedures). This force standard facility gives traceability to measurements (and calibrations) made by the net of secondary...
Cultivating Metrological Knowledge
· TC3
· 2007
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C. Marinari, F. Mazzoleni, J. C. Torres-Guzman,D. A. Ramirez-Ahedo
In order to improve the metrological characteristics of the primary force standard machines, as well as to understand the causes of anomalies and to optimise calibration methods, it is important to measure the value and the effect of the parasitic components which could influence the final value and uncertainty of the applied vertical loads. The paper describes the measurements performed on the 150 kN CENAM (Mexico) primary force standard deadweight machine in order to evaluate the value and the direction of the parasitic components (two side forces F X and F Y ; two bending moments F L and...
Cultivating Metrological Knowledge
· TC3
· 2007
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Juan Benjamin Soriano Cardona, Manuel Segura Galindo
A review of mass calibration of pressure balance weights was developed to explain in detail the considerations around the measurements of mass value determination of each weight applied on the pressure balance that use an accurate mathematical model by industrial and accredited laboratories. The mass value determination of each weight applied on the pressure balance is an important uncertainty contribution in the estimation of the uncertainty measurement of a pressure balance when used for the calibration of another measuring instrument and in the case where the total measurement uncertainty...
Cultivating Metrological Knowledge
· TC16
· 2007
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G. Buonanno , J. Man, G. Molinar Min Beciet
The National Measurement Institute of Australia (NMIA) and the Istituto Nazionale di Ricerca Metrologia of Italy together with the University of Cassino (INRIM/UNICAS) have participated in a research project to characterise a INRIM 100 MPa free deformation piston and cylinder assembly using two different numerical procedures based on a finite element method (FEM). The pressure distortion coefficient, ? and the piston fall rates, v were calculated from the clearance profile between the piston and cylinder obtained from dimensional measurement data. Comparison of the numerical results obtained...
Cultivating Metrological Knowledge
· TC16
· 2007
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M. Caravaggio, G. Molinar Min Beciet, P. De Maria, G. Buonanno, G. Giovinco
The main purpose of this work is the numerical and experimental analysis of an industrial pressure balance operating in liquid media up to 120 MPa. The numerical prediction of the pressure distortion coefficient, the piston fall rates, the piston-cylinder elastic distortions is achieved through the Finite Element Method (FEM). Numerical results are compared to experimental values and a sensitivity analysis is performed in order to explain some differences between FEM and experimental results.
Cultivating Metrological Knowledge
· TC16
· 2007
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