International and National Journals

M. Astrua, D. Ichim, F. Pennecchi, M. Pisani
Statistical techniques for assessing the agreement between two instruments
Metrologia, Vol. 44, no. 5, pp. 385-392, 2007 (IF 1,667).

The comparison of two methods of measurement or instruments is addressed from a statistical point of view. Several techniques for assessing the degree of conformity between two methods/instruments measuring the same quantity are discussed and compared. Their application in the framework of angle measurements is presented.

P. Becker, G. Cavagnero, U. Kuetgens, G. Mana, E. Massa
Confirmation of the INRiM and PTB determinations of the Si lattice parameter
IEEE Transactions on Instrumentation and Measurement, Vol. 56, no. 2, pp. 230-234, 2007 (IF 0,832).

Measurements of the (220) lattice plane spacing of Si by combined x-ray and optical interferometry, which had been carried out to resolve a discrepancy between previous determinations, have been reported. However, it was subsequently found that the laser beam used to measure the displacement of the X-ray interferometer was contaminated by a parasitic component having a different optical frequency. The new measurement results given here are intended to assess the relevant correction.

P. Becker, P. De Bievre, K. Fujii, M. Glaeser, B. Inglis, H. Luebbig, G. Mana
Considerations on future redefinitions of the kilogram, the mole and of other units
Metrologia, Vol. 44, pp. 1-14, 2007 (IF 1,667).

The definitions of some units of the Systeme International are likely to be revised as early as 2011 by basing them on fixed values of fundamental constants of nature, provided experimental realizations are demonstrated with sufficiently small uncertainties. As regards the kilogram, experiments aiming at linking it to the Planck constant and the atomic mass constant are under way in several laboratories. The other units likely to be redefined are the ampere, the kelvin and the mole. We discuss the advantages and disadvantages of different alternatives for revised definitions of the kilogram and the mole. From physical considerations, metrological consequences and ease of understanding, a definition of the kilogram based on the mass of a particle, such as an atom or the electron, is favoured. One of the proposed definitions fixes the value of the Planck constant through the Compton frequency of a material, though unphysical, particle. Finally, a redefinition of the mole, the counting unit of the amount-of-substance, is proposed which fixes the Avogadro constant as a dimensionless number.

A. Calcatelli, M. Bergoglio, D. Mari
Leak detection, calibrations and reference flows: Practical example
Vacuum, Vol. 81, nos. 11-12, pp. 1538-1544, 2007 (IF 0,881).

The most diffused leak detection method for the leak rates lower than 10^-2 mbar L/s that is based on the application of mass spectrometry with tracer gas (generally helium) is considered. A description is given of the metrological characterization of the mass spectrometer leak detectors (MSLD) for industrial applications since they represent the best choice for tightening tests having good sensitivity and high testing speed. The calibration of MSLDs is performed with reference to known gas flow-rates as given by the so-called standard leaks which may generate flow from 10^-8 to 10^-2 mbar L/s; these leaks are calibrated against primary gas flow-meters which, at INRIM, cover the gas flow-rate ranges from 2×10^-8 to 1×10^-3 mbar L/s. As an example a device for on-line tests on components is presented together with the results of the calibrations against reference leaks of the MSLD alone and when it is inserted in a complete machine. By taking into account all the factors contributing to the uncertainty evaluation, a relative expanded uncertainty smaller than 20% may be reached.

L. Callegaro, F. Pennecchi
Why always seek the expected value? A discussion relating to the Lp norm
Metrologia, Vol. 44, pp. L68-L70, 2007 (IF 1,667).

The process of estimating a measurand is based on the choice of an appropriate estimator. The metrologist usually makes this choice by comparing estimator properties such as unbiasedness, efficiency and robustness. We show that when dealing with asymmetric parent distributions, the expected value might not correspond to the measurand value; hence it might not be the correct parameter to estimate. In such cases, another location parameter can fit the measurand better and the properties of candidate estimators should be assessed in relation to such parameters. The paper discusses two examples with reference to the class of the L_p parameters and estimators, which include several commonly used in metrology.

H. Fujimoto, G. Mana, K. Nakayama
A possible solution for the discrepancy between the INRIM and NMIJ values of the Si lattice-parameter
IEEE Transactions on Instrumentation and Measurement, Vol. 56, no. 2, pp. 351-355, 2007 (IF 0,832).

We present the results of a joint project to identify the origin of a discrepancy between the value of the Si lattice- parameter obtained by the Istituto Nazionale di Ricerca Metrologica and that obtained by the National Metrology Institute of Japan. The re-evaluation of diffraction in the laser interferometry indicates that misalignment of the interfering beams could account for the observed difference.

G. Galzerano, G. Mana, E. Massa
On the effect of broadband emission in external-cavity diode-laser interferometry
Measurement Science and Technology, Vol. 18, no. 5, pp. 1338-1342, 2007 (IF 1,297).

When external-cavity diode lasers are used in dimensional metrology via optical interferometry, parasitic modes and background radiation deserve careful investigation. This paper gives the relevant measurement equation and explicit formulae for the excess phase of travelling fringes. Particular emphasis is given to potential errors in the measurement of the Si lattice parameter by combined x-ray and optical interferometry.

G. Lamporesi, A. Bertoldi, A. Cecchetti, B. Duhlach, M. Fattori, A. Malengo, S. Pettorruso, M. Prevedelli, G. M. Tino
Source mass and positioning system for an accurate measurement of G
Review of Scientific Instruments, Vol. 78, p. 075109, 2007 (IF 1,384).

We report on a system of well-characterized source masses and their precision positioning system for a measurement of the Newtonian gravitational constant G using atoms as probes. The masses are 24 cylinders of 50 mm nominal radius, 150.2 mm nominal height, and mass of about 21.5 kg, sintered starting from a mixture of 95.3% W, 3.2% Ni, and 1.5% Cu. Density homogeneity and cylindrical geometry have been carefully investigated. The positioning system independently moves two groups of 12 cylinders along the vertical direction by tens of centimeters with a reproducibility of a few microns. The whole system is compatible with a resolution ΔG/G 10^-4.

L.-S. Ma, Z. Bi, A. Bartels, K. Kim, L. Robertsson, M. Zucco, G. Wilpers, C. Oates, L. Hollberg, S. A. Diddams
Frequency Uncertainty for Optically Referenced Femtosecond Laser Frequency Combs
IEEE Journal Of Quantum Electronics, Vol. 43, pp. 139-146, 2007 (IF 2,360).

We present measurements and analysis of the currently known relative frequency uncertainty of femtosecond laser frequency combs (FLFCs) based onKerr-lens mode-locked Ti:sapphire lasers. Broadband frequency combs generated directly from the laser oscillator, as well as octave-spanning combs generated with nonlinear optical fiber are compared. The relative frequency uncertainty introduced by an optically referenced FLFC is measured for both its optical and microwave outputs. We find that the relative frequency uncertainty of the optical and microwave outputs of the FLFC can be as low as 8 × 10²⁰ and 1.7 × 10¹⁸, with a confidence level of 95%, respectively. Photo-detection of the optical pulse train introduces a small amount of excess noise, which degrades the stability and subsequent relative frequency uncertainty limit of the microwave output to 2.6 × 10¹⁷.

G. Mana, F. Pennecchi
Uncertainty propagation in non-linear measurement equations
Metrologia, Vol. 44, no. 3, pp. 246-251, 2007 (IF 1,667).

When non-linearity is significant, the determination of the combined standard uncertainty requires that at least third order terms are retained in the Taylor approximation of the measurement equation. Hence, if the input variables follow a multivariate normal distribution, approximate expressions exist for the mean and combined uncertainty of the estimator.

F. Marinello, P. Bariani, A. Pasquini, L. De Chiffre, M. Bossard, G. B. Picotto
Increase of maximum detectable slope with optical profilers, through controlled tilting and image processing
Measurement Science and Technology, Vol. 18, p. 384, 2007 (IF 1,297).

Optical methods are of choice in a huge number of applications. In particular, those instruments based on vertical scanning methods provide extremely fast, non-contact characterization of surface topography. However some limitations are present. Among them, maximum detectable slope is limited (generally <30º). Local loss of signal, resulting from this limited detection, originates data files containing void pixels, which eventually provide poor surface characterization. This work presents an original approach to overcome instrumental limitation on the maximum detectable slope. The method presented here is based on a software tool that processes images taken with controlled tilt, and returns a high-quality 3D profile of the sample being investigated. Experimental evidence is given with reference to the case of a Vickers indentation on steel.

M. Pisani, M. Zucco
Hyperspectral imager captures whole spectrum without scanning
Laser Focus World, p. 15, 2007 (IF 0,245).

A. Rivetti, G. Martini, F. Alasia, G. La Piana, L. Gatti
BIC3, the latest inertial centrifugal balance for mass measurement in weightless conditions
Microgravity Science and Technology, Springer Netherlands, published on-line 4 December 2007 (IF 0,467).

The paper describes BIC 3, the latest prototype of inertial balance made at INRIM in view of its possible use on board the International Space Station. The main characteristic of this instrument is its ability to work both in weightless conditions and on Earth surface with metrological performances comparable to those of a laboratory-level classic balance. BIC 3, although still based on the same centrifugal method adopted in the two previous prototypes, widely differs from them as regards configuration (constant speed), main motor characteristics (here a stepping motor is used), force transducer (the integral beam of a commercially-available balance), and consequently shows metrological performances considerably improved. The main constructional features are described and the metrological characteristics resulted from on-Earth tests are reported and discussed. A test made of 175 measurements in the range 0 - 150 g showed an expanded uncertainty of 4.1 mg.

L. Robertsson, M. Zucco, R. Felder, L.-S. Ma, A. M. Dahlan, E. Prieto, M. Perez, F. Saraiva, R. Sharma
Results from the CII-2005 and CI-2006 campaigns at the BIPM of the BIPM.L-K11 ongoing key comparison
Metrologia, Vol. 44, Tech. Suppl, 2007 (IF 1,667).

Lasers from four national metrological institutes (NMIs) were brought to the BIPM in November 2005 and May 2006 as part of the BIPM.L-K11 ongoing key comparison initiated by the Comité Consultative des Longueurs (CCL) 11^th meeting in 2003. The absolute frequency of the f component of the R(127) 11-5 transition was measured for these lasers following the Protocol for BIPM.L-K11. The results of these measurements are compiled in the present paper. The comparison reports, as communicated by each participant, are included as Appendices.

L. Robertsson, M. Zucco, R. Felder, L.-S. Ma, J. Quin, X. Liu, Z. Liu, H. Inaba, J. Ishikawa, R. Hamid
Results from additional measurements carried out within the BIPM.L-K11 ongoing key comparison
Metrologia, Vol. 44, Tech. Suppl, 2007 (IF 1,667).

Lasers from three national metrological institutes (NMIs) have been measured following the protocol of the BIPM.L-K11 ongoing key comparison initiated by the Comité Consultative des Longueurs (CCL) 11^th meeting in 2003. The absolute frequency of the f component of the R(127) 11-5 transition at 633 nm was measured for two of these lasers in their home institutes, AIST/NMIJ and UME, while the b5 component of the R(106) 28-0 transition at 543 nm was measured on a standard from NIM at the BIPM. The results of these measurements are compiled in the present paper. The comparison reports, as communicated by each participant, are included as Appendices.

M. Caravaggio, G. Molinar Min Beciet, P. De Maria
Pressure balance for industrial applications up to 120 MPa
MAPAN- Journal of Metrology Society of India, Vol. 22, n. 44, pp. 231-234, 2007.

The design and development of a series of pressure balances, operating in liquid media up to 120 MPa and in gas media up to 12 MPa, have been started during a recent collaboration between the Italian company SCANDURA & FEM and the I.N.RI.M (Italian National Research Institute of Metrology) in Italy. The details of the project design for the pressure balance in liquid media up to 120 MPa are here presented. The chosen strategy has been decided in such a way to produce a compact pressure balance easy to move, but at the same time equipped with all the measuring sensors needed to compensate the errors due to the main influence quantities. The main metrological characteristics of some piston-cylinder units were experimentally carried out and some interesting results are here presented.

M. Bergoglio, A. Calcatelli
Rivelazione e misurazione delle fughe (parte prima)
Il giornale delle prove non distruttive, n. 3, pp. 71-84, 2007.

W. Bich, M. Cibien
Guida all'espressione dell'incertezza di misura (GUM): il punto della situazione
Unificazione e Certificazione, n. 1, pp. 9-10, 2007.

W. Bich, M. Cibien
Guida all'espressione dell'incertezza di misura (GUM): il punto della situazione
Eidos, n. 1, pp. 42-44, 2007.

Si riferisce sulla riunione del Comitato tecnico "Flow" di EUROMET tenuta nel marzo 2007 ad Istanbul, nella quale sono stati esaminati stato di avanzamento e risultati dei confronti chiave e degli altri progetti di collaborazione fra i metrologi del settore in Europa. Vengono citati i nuovi progetti di ricerca che sono stati decisi . Si conclude con una descrizione della visita ai nuovi grandi impianti per misure di liquidi e di gas costruiti presso l'Istituto Metrologico Turco UME.

G. D'Errico
Dal disegno industriale alla verifica di conformità
Utensili & Attrezzature, pp. 56-59, gennaio 2007.

Si considera la qualità del prodotto nel corso del processo manifatturiero, con particolare riguardo alla verifica per mezzo di ispezioni dimensionali. Sono focalizzati alcuni aspetti normativi e metrologici di interesse per la competitività nello scenario internazionale, con applicazioni alla tecnologia meccanica e alle macchine di misura a coordinate.

A. Germak, A. Liguori
La Metrologia Primaria italiana è sempre più internazionale
Ingegneri di Bergamo, n. 188, p. 14, 2007.

La Metrologia Primaria italiana è oggi sempre più internazionale: infatti, ha di recente ed in più occasioni, varcato i confini nazionali per recarsi con successo anche oltreoceano. Più precisamente verso l'Istituto Metrologico Primario del Brasile (INMETRO), oppure verso il NIM, l'analogo istituto di Pechino in Cina, oppure raggiungendo la Bulgaria all'NCM, come aveva già fatto in passato approdando al NIST negli USA. Presto, sarà anche in India all'NPL. Stiamo parlando del durometro campione primario progettato e come prima installazione, realizzato all'Istituto Nazionale di ricerca Metrologica (già Istituto di Metrologia "G. Colonnetti" (IMGC) del CNR) a Torino e successivamente ceduto, come licenza di sfruttamento di know-how, alla divisione Galileo Durometria dell'LTF Spa di Antegnate (BG).

Conference Proceedings

R. Arina, R. Malvano, A. Piccato, P. G. Spazzini
Numerical and experimental analysis of sound generated by an orifice
Proceedings of the 13^th AIAA/CEAS Aeroacoustics Conference (28^th AIAA Aeroacoustics Conference) - Rome (Italy) - May 2007. AIAA Paper 2007-3404.

The present paper deals with noise produced by an orifice placed in a circular duct. Such noise is mainly generated by the orifice itself and by the unsteady flow and turbulence in the orifice wake. The main objective of the present work is to develop a numerical prediction tool for the acoustic energy level produced by the orifice placed in a ducted flow. The model is based on the solution of the Navier-Stokes equations, for the compressible turbulent flow, inside the duct and in the near-region outside the duct termination, and on the Ffowcs Williams-Hawkings surface method for the evaluation of the far-field acoustic radiation. Experimental measurements were also performed; such data are used to validate the numerical model. The measured and computed sound pressure level directivities are in good agreement, and show the influence of the orifice on sound generation. The numerical results are in good agreement with the law, relating the fluctuating drag force acting on the orifice and the steady drag force, proposed in the theory of Nelson and Morfey (1981).

P. Becker, M. Jentschel, G. Mana, G. Zosi
Towards an atomic realization of the kilogram: the measurements of N_A and N_Ah
Proceedings of the International School of Physics "Enrico Fermi", Course CLXVI "Metrology and Fundamental Constants", edited by T. Hänsch, S. Leschiutta, A. J. Wallard and M. L. Rastello, pp. 519-532, IOS Press 2007.

The paper will survey a collaboration aimed at accurate measurements of nuclear binding energies to determine the product N_Ah - molar Planck's constant. The measurement is based on the fact that, in a neutron capture reaction, the daughter isotope is slightly lighter then the ensemble formed by mother isotope and the neutron. This mass difference is equal to the binding energy and can be measured by determining the frequencies of the x-ray cascade in the decay scheme of the capture-state. In principle, nuclear transitions can set time, length, and mass via the frequency and wavelength of the emitted x-rays and the mass differences between the relevant energy levels. Although, for what concerns time and length this is far beyond today capabilities, nuclear transitions open the way to measurements of atomic masses in terms of frequency measurements, provided measurements are performed at the required 10^-8 accuracy level. The way from the atomic to the macroscopic scales is extremely difficult and it is presently limited to 10^-7 accuracy. We then consider a second international effort to realize a macroscopic mass to within 10^-8 accuracy from the counting of the individual atomic constituents of a 1 kg ²⁸Si crystal-sphere.

W. Bich
Recent developments in uncertainty evaluation
Proceedings of the International School of Physics "Enrico Fermi", Course CLXVI "Metrology and Fundamental Constants", edited by T. Hänsch, S. Leschiutta, A. J. Wallard and M. L. Rastello, pp. 81-94, IOS Press 2007.

The publication in 1993/1995 of the Guide to the Expression of Uncertainty in Measurement, GUM, stimulated a great development of research concerning measurand estimation and uncertainty evaluation. The application of the GUM method has brought into light its merits and limits. This paper reviews them and discusses the recent evolution of concepts and methods in the specific field of uncertainty evaluation.

W. Bich, F. Pennecchi
Developments in uncertainty evaluation: the activity of JCGM/WG1
Proceedings of the International Workshop pp. 117-126, IUPAC-APAT, Royal Chemical Society Publishing, London 2007.

W. Bich, G. D'Agostino, A. Germak, F. Pennecchi
Uncertainty propagation in a non-linear regression analysis: application to a ballistic absolute gravimeter (IMGC-02)
Proceedings of the Workshop Advanced Methods for Uncertainty Estimation in Measurement, Sardagna (TN), July 2007, ed. IEEE I&M (cd rom).

Today's most accurate measurements of the gravitational acceleration are based on interferometric reconstruction of the vertical trajectory followed by a test body launched in a vacuum chamber. The gravity value g is one of the parameters of a model function derived from the law of motion of the body, and is estimated by a least squares adjustment. In this paper we present the regression analysis applied to the IMGC-02 absolute gravimeter and the associated uncertainty propagation. We also show how a suitable choice of the reference height z, at which g is calculated, can yield a minimum-variance estimate. This choice is based on the covariance matrix of the parameter estimates provided by the adjustment algorithm.

G. Buonanno, J. Man, G. Molinar Min Beciet
The characterization of IMGC-DH100L pressure balance through the finite element analysis
Proceedings of 7^th Metrology Society of Australia Conference, pp. 70-75, Adelaide (Australia), July 2007.

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, λ 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 by the two groups showed a relative difference of 2×10^-4 in λ and 2.5×10^-2 in v. The numerical results were also compared to the experimental results with a relative difference of 1.9 % in λ and 16 % at 100 MPa in v. This paper presents the numerical model used for the calculations of the pressure distortion coefficient and the piston fall rates with a sensitivity analysis of the model for the estimation of the uncertainty values of these two parameters.

M. Caravaggio, G. Molinar Min Beciet, P. De Maria
Series of pressure balances for industrial use
Proceedings of the 13^thInternational Metrology Congress, Lille (France), June 2007 (cd rom).

The design and development of a series of pressure balances, operating in liquid media up to 120 MPa and in gas media up to 12 MPa, started during a recent co-operation between Italian company SCANDURA & FEM and I.N.RI.M (Italian National Research Institute of Metrology). The details of the project design for the pressure balance in liquid media up to 120 MPa are here presented with particular emphasis on the piston motor drive. The main metrological characteristics of some piston-cylinder units were experimentally determined and some key results are here reported.

M. Caravaggio, G. Molinar Min Beciet, P. De Maria, G. Buonanno, G. Giovinco
Industrial pressure balance up to 120 MPa in liquid: FEM analysis and comparison with experimental data
Proceedings of 7^th Metrology Society of Australia Conference, pp. 64-69, Adelaide (Australia), July 2007.

The design and the latest developments of several pressure balances operating in liquid medium up to 120 MPa started within a cooperation between the Istituto Nazionale di Ricerca Metrologica (INRiM) and the Scandura & FEM company. These pressure balances are used for industrial purposes: they must be compact, easy to move and to use, equipped with many sensors in order to compensate the main influence quantities affecting pressure measurements. In the paper the design criteria and the results obtained from experimental measurements (piston fall rate versus pressure, effective area and its variation with pressure, rotation rate, sensitivity, ..) are given and evaluated. In order to validate the main metrological characteristics of a pressure balance operating up to 120 MPa and also to supply the design of the piston-cylinder unit with numerical results, the cooperation was extended to the University of Cassino that in the last 10 years successfully applied finite element methods (FEM) in the numerical analysis of different pressure balances. FEM results, particularly in terms of piston fall rates, of pressure distortion coefficient and of their estimated uncertainties, are presented and compared with the experimental ones. A full analysis of the influence of geometrical shape, of the elastic constants of piston and cylinder materials, of fluid properties is considered in order to supply information for the validation of different pressure balances during their production.

M. Caravaggio, G. Molinar Min Beciet, P. De Maria, G. Buonanno, G. Giovinco
FEM Analysis for an industrial pressure balance from 3 MPa to 120 MPa in liquid medium
Proceedings of IMEKO TC 16 International Conference, Merida (Mexico), November 2007 (cd rom).

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.

A. Cumani, A. Guiducci
Visual odometry with SURFs and déjà vu correction
Proceedings of the VIII Optical 3D Measurement Techniques Conference, pp. 295-299, Zurich (Switzerland), July 2007 (on cd rom too).

This work deals with the problem of estimating the trajectory of an autonomous rover by onboard passive stereo vision only (so-called Visual Odometry). The proposed method relies on bundle adjustment of tracked SURF feature points. In the case of cyclic trajectories, accumulated errors are corrected by comparing the scene against a set of stored references.

S. Lorefice, A. Malengo, M. Caravaggio, L. Cianciotta
Design of an automatic apparatus for the calibration of on-line densimeters
Proceedings of IMEKO TC 16 International Conference, Merida (Mexico), November 2007 (cd rom).

The design and the expected performance of a new apparatus suitable to satisfy the traceability requirements in the density field is here presented. The apparatus is mainly intended to measure liquid density range between 500 kg/m³ and 3000 kg/m³ and to evaluate the performance of on-line densimeters during the actual use, i.e. the same process liquid under similar flow conditions. Details about the hardware components of the system and the software programs are also given. By using an instrument not specifically selected and calibrated for the intended working conditions, the value of u_instr(ρ)= 0.20 kg / m³ is the lowest expected uncertainty of density measurements of fluids. However, higher accuracy can be established for the selected reference instrument by the use of the same fluids employed in the process at the usual operative conditions and whose densities are certified by national metrological institutes (NMIs) or accredited laboratories.

C. Marinari, F. Mazzoleni, J. C. Torres-Guzman, D. A. Ramirez-Ahedo
Evaluation of the CENAM (Mexico) 150 kN primary force standard machine by means of the INRIM 100 kN six-component dynamometer
Proceedings of IMEKO TC 16 International Conference, Merida (Mexico), November 2007 (cd rom).

The use of the INRiM composite six-component dynamometer has made possible an advancement in the analysis of force standard machines behaviour since with it, is possible, beside determining the force hexavector, to associate this quantity to the different operational parameters, such as load level, weights combination, load application rate, among others. This paper describes the measurements performed on the 150 kN CENAM (Mexico) primary force standard deadweight machine in order to evaluate the main vertical load, the value and the direction of the parasitic components (two side components F_X and F_Y; two bending moments F_L and F_M, and the twisting moment F_N) generated by the standard machine. The influence of the parasitic components on the Force Standard Machine accuracy is studied as well. Special testes were also carried out to evaluate the influence of different weight-piece combinations, the different load application rates, the consequent weight-piece oscillations and the vertical position of the adjustable cross-beam.

C. Marinari, A. Germak, J. C. Torres-Guzman, D.l A. Ramirez-Ahedo
Comparison between the CENAM (Mexico) 150 kN and the INRIM (Italy) 1 MN force standard machines
Proceedings of IMEKO TC 16 International Conference, Merida (Mexico), November 2007 (cd rom).

The present paper describes the results of a bilateral comparison carried out between the CENAM (Mexico) 150 kN deadweight force standard machine and the INRiM (Italy) 1 MN deadweight force standard machine. This force comparison was carried in order to estimate the level of agreement for the realization of the quantity and the uncertainty associated to its measurement. This constitutes the first force comparison between the two institutions.The paper describes the two deadweight force machines, their main metrological characteristics and the procedure of the comparison. The main results of the comparison with the relevant uncertainties of the measurements carried out at CENAM and at INRiM are presented. The final evaluation of the agreement between the measurements performed by the two National force standard machines is given.

R. Malvano, P. G. Spazzini, A. Piccato
Calibration of a cup anemometer on a rotating arm rig
Proceedings of the 14^th International Flow Measurement Conference (FLOMEKO14), Johannesburg (South Africa), September 2007.

The present work deals with calibration of cup anemometers. I.N.Ri.M. uses wind tunnels for anemometer calibration at high speeds, but this kind of test rigs is not appropriate for the calibration at low speeds, in particular for determining the instrument threshold. For this kind of measurements, a test rig consisting in a rotating arm (which allows long run times at nominal speeds in the range from 0.20 to 5.0 m/s) is used. Due to their working principle, cup anemometers react to the rotating environment in a different way with respect to their response to an analogous stimulus in a uniform flow. Though, it is possible to theoretically compute this difference and to derive a correction formula. A mathematical derivation of the correction formula is shown for a simplified case together with experimental results, in order to show the extent of the problem and the validity of the solution proposed.

J. Man, G. Molinar Min Beciet, G. Buonanno, G. Giovinco
Numerical characterization of a 10 Mpa pressure standard based on dimensional data
Proceedings of 7^th Metrology Society of Australia Conference, pp. 70-75, Adelaide (Australia), July 2007.

Workers at the National Measurement Institute of Australia (NMIA) and the Italian National Research Institute of Metrology and the University of Cassino (INRIM/UNICAS) have carried out a numerical characterisation of a NMIA 10 MPa free deformation piston and cylinder assembly using two different numerical procedures based on a Finite Element Method (FEM). The effective area, A₀ and the pressure distortion coefficient,λ and the piston fall rate of the 10 MPa p-c unit were determined from the actual clearance profile between the piston and the cylinder obtained from dimensional measurement data. Comparison of the calculated values of A₀ and λ obtained by the two groups showed a relative difference of 1 × 10^-7 in A₀, 5 × 10^-3 in λ and 0.4 % in piston fall rate. This paper presents the numerical model used for the characterisation with a sensitivity analysis of the model for the estimation of an uncertainty value of the pressure distortion coefficient.

S. Masala, P. Pedone, M. Sandigliano, D. Romano
Product/Process improvement by integrated Physical and simulation experiments: a case-study in the textile industry
Proceedings of the 7^th ENBIS International Conference, Dortmund (Germany), September 2007.

In hi-tech industry, like aerospace and microelectronics, simulation and lab tests are routinely used together in the product/process development phase. However, although Design of Experiments and Computer Experiments are sound methodologies for running experiments in physical and numerical settings respectively, effective integration between the two kinds of investigation in view of product/process improvement and innovation is little explored in academic literature. The paper presents a broad approach for this purpose. Although the approach is still qualitative, it introduces the various elements of an industrially relevant problem which is likely to challenge applied statisticians in the near future. The approach is illustrated by its application to a manufacturing process in the textiles.

M. Pisani, M. Astrua
Sub-nanoradian angle measurements
Nanotech IT Newsletter, pp. 8-11, June 2007.

A method to measure very small rotations based on the angle amplification experienced by a ray which is reflected between two quasi-parallel mirrors is presented. The method is simple and allows high angular sensitivities to be obtained without the need of ultrastable mechanical structures, since the sensitive area is very compact. A noise limited sensitivity better than 0.1 nrad has been demonstrated. Besides the obvious applications in the field of angle metrology, it is expected that the technique can find applications in all the experiments where a very small rotation must be measured and/or controlled.

P. G. Spazzini, O. Caramia
Simulation of a Sonic Nozzle By a Numerical Code
Proceedings of the 14^th International Flow Measurement Conference (FLOMEKO14), Johannesburg (South Africa), September 2007.

The present work describes the numerical simulation of a sonic nozzle performed by a commercial numerical code. The main objective of the work was to assess the reliability of such codes as tools for metrological work. The paper briefly describes the background of numerical simulation of fluid flows, and recalls the main formulations of common use in sonic nozzle analysis. The results show that, for a test case with a well-defined geometry and relatively simple boundary conditions, commercial CFD codes can be a useful support tool for metrological analysis.

P. G. Spazzini, V. Todde, M. Sandberg
Low-speed measurements using a hot-wire anemometer
Proceedings of the 14^th International Flow Measurement Conference (FLOMEKO14), Johannesburg (South Africa), September 2007.

In the present work, a method for calibrating hot-wire anemometers for low-speed measurements is described. After a brief recall of the working principle of the instrument, the problems connected with the measurement of low-speed flows are described. A method for overcoming these problems is proposed, and the special features of the specific calibration are discussed. Two different mathematical treatments of the calibration data are analyzed and compared. Finally, some test measurements are presented, showing that the results are in line with the expectations.

G. D'Agostino, A. Germak, C. Origlia, D. Quagliotti
Perturbations in absolute gravimetry: a quantitative estimate of some of the most overriding influence factors
Proceedings of Symposium on Terrestrial Gravimetry: Static and Mobile Measurements, pp. 117-122, St. Petersburg (Russia), Russian Federation, August 2007.

Absolute gravity measurements are based on the reconstruction of the free-falling motion of a test body in vacuum. Several works concerning influence phenomena are available in literature and can be used in evaluating the measurement uncertainty. The statistical analysis of series of observations is useful to evaluate some components of this uncertainty but the remaining ones must be derived from a priori probability distributions of the unknown parameters affecting the result. In this paper the propagation of the probability distributions using a Monte Carlo method is showed to be a powerful tool to estimate the effect of two non-gravitational accelerations introduced by translations and rotations of the flying object: the Coriolis and centripetal acceleration. We discuss the analysis applied to the IMGC-02 absolute gravimeter.

G. D'Agostino, A. Germak, L. F. Vitushkin
International comparison of absolute gravimeters: technical protocol and estimate of the reference value and its uncertainty
Proceedings of Symposium on Terrestrial Gravimetry: Static and Mobile Measurements, p. 116, St. Petersburg (Russia), Russian Federation, August 2007.

One of the ways to highlight systematic errors in measuring a physical quantity is to compare the results obtained with instruments adopting different measurement principles and methods. It's likely that instruments applying the same measurement technique provide correlated results. The data processing should estimate this correlation in order to correctly evaluate the final comparison reference value. Special attention should be also given to the correct evaluation of the measurement uncertainty in order to compute the comparison reference value as a weighted mean and to evaluate its uncertainty. The Bureau International des Poids et Mesures (BIPM) regularly organizes International Comparisons of Absolute Gravimeters (ICAGs), where a considerable number of instruments measure practically at the same time and at the same position the gravity field. In the past, for participating ICAGs the evaluation of the uncertainty was not compulsory and the reference (in fact, simply averaged) value was computed without weighing the results. Recently the scientific community decided to carry on the ICAGs under the rules of the CIPM (Comité International des Poids et Mesures) key comparisons and the needs of a correct evaluation of the measurement uncertainty became necessary. A tentative was done in conducting the last ICAG05 as Pilot Study trying to apply the same rules of the CIPM key comparisons. The proposed paper discusses the technical protocol followed during the last ICAG05, which was considered a pilot study of a CIPM key comparison, and the equations used to compute a possible reference value and its uncertainty are described in details.

A. Germak, A. Liguori,C. Origlia
Experience in the metrological characterization of primary hardness standard machines
Proceedings of IMEKO TC5 - HARDMEKO 2007, Recent Advancement of Theory and Practice in Hardness Measurements, pp. 78-86, Tsukuba (Japan), Nov. 2007.

The Istituto Nazionale di Ricerca Metrologica (INRIM) and Galileo section of LTF S.p.a. have cooperated for many years in the field of hardness for developing and improving Primary Hardness Standards and measuring systems for their laboratories. With this experience, Galileo-LTF has realized many installations for several NMIs in the world. All these Hardness Standards and measuring systems have been metrologically characterised by INRIM. In the paper, experiences made during the metrological characterization will be shown. They include the methods and results of direct verification of influence parameters (force, displacement, time, velocity, angle, etc.) and of indirect verification (hardness scales or indenters comparison) of the systems.

A. Germak, C. Origlia
Analysis and estimation of possible large systematic error in Brinell hardness measurements
Proceedings of IMEKO TC5 - HARDMEKO 2007, Recent Advancement of Theory and Practice in Hardness Measurements, pp. 73-77, Tsukuba (Japan), Nov. 2007.

Brinell hardness measurements are widely used at industrial level. For the calculation of Brinell hardness values, the measurement of the diameter of indentations is necessary. In practice, the measurement of the image created by the optical systems used for the magnification of the indentation is usually carried out. The dimension of the indentation image depends by the optical system that, in practice, transform the real indentation in image using properties of light reflection. The paper describe the effect of this influence parameter in Brinell hardness measurements in experiments carried out at hardness laboratory of Istituto Nazionale di Ricerca Metrologica (INRIM) (formerly Istituto di Metrologia "G. Colonnetti" - IMGC) with application to the data obtained at international comparison at the National Metrology Institutes level. Moreover, some methods for its evaluation and possible correction will be proposed.

P. Allasia, S. Denasi, G. Quaglia
Misura mediante telecamere di piccoli spostamenti nel monitoraggio di fenomeni di dissesto naturale
Atti del V Congresso Metrologia & Qualità, Torino, marzo 2007 (cd rom).

P. Allasia, S. Denasi, G. Lollino, G. Quaglia, C. Rivarossa
Monitoraggio di fenomeni di dissesto naturale mediante elaborazione in tempo reale d'immagini
Atti 11ª Conferenza Nazionale ASITA, Torino, nov. 2007 (cd rom).

L'articolo proposto descrive l'attività sperimentale volta a valutare le prestazioni di tecnologie video e di elaborazione immagini per misurare in tempo reale piccoli movimenti di superficie in aree soggette a dissesto geo-idrologico. Le tecnologie basate sull'elaborazione di immagini riprese da una telecamera consentono misure di movimento senza interventi in corpo frana. Il sistema proposto utilizza bersagli naturali (rocce, licheni, ecc.) come elementi di riferimento per misurare eventuali spostamenti mediante il confronto di immagini successive. Un sistema sperimentale è stato installato presso la stazione di monitoraggio del CNR-IRPI presso la frana di Gardiola in Val Germanasca (Torino). Utilizzando una telecamera BN progressiva, con un sensore CCD di 640 x 480 pixel di 7.4 x 7.4 µm ed equipaggiata con un teleobiettivo di focale pari a 300 mm si è verificato che il sistema è in grado di misurare spostamenti di qualche mm usando semplici riferimenti naturali (licheni, rocce). Queste prestazioni hanno permesso di evidenziare uno spostamento dell'area monitorata di circa 75 mm avvenuto tra il 12 e 23 dicembre 2004 in pieno accordo con le misure effettuate dalla stazione totale. Attualmente, allo scopo di estendere l'area monitorata e migliorare le prestazioni fornite dal sistema si è provveduto ad una completa robotizzazione della telecamera installando una movimentazione per brandeggiare orizzontalmente e verticalmente il sistema di ripresa ed è stato sviluppato un nuovo algoritmo per la misura degli spostamenti basato sull'identificazione automatica di punti caratteristici dell'immagine invarianti all'illuminazione.

R. Bellotti, G.B. Picotto, M. Pisani, M. Pometto
Taratura di reticoli 1D, 2D e righe ottiche
Atti del V Congresso Metrologia & Qualità, Torino, marzo 2007 (cd rom).

M. Bergoglio, D. Mari
Il ruolo delle misure di flusso di gas e di pressione nella ricerca delle perdite
Atti del 12º Congresso nazionale sulle prove non distruttive, Milano, ottobre 2007 (cd rom).

Le prove di tenuta, siano esse eseguite a livello di collaudo del prodotto o siano più sofisticate, per quantificare la tenuta di un prodotto, richiedono la misura di varie grandezze quali la pressione, il flusso di gas, la temperatura, la concentrazione del gas utilizzato per la prova. Per queste grandezze, così come per tutte le grandezze fondamentali e derivate del sistema SI (Sistema Internazionale delle unità di misura), è stata realizzata la catena della riferibilità che parte dai campioni primari, conservati presso l'INRIM, passa attraverso i campioni di riferimento dei Laboratori Secondari e si diffonde ai campioni di lavoro utilizzati dall'industria. Nella prima parte del lavoro vengono presentati in modo sintetico i campioni primari per la misura della pressione e del flusso di gas e vengono indicate le caratteristiche metrologiche salienti dei trasduttori di trasferimento di pressione e delle fughe di riferimento. Nella seconda parte del lavoro si mette in rilievo l'importanza che assume, ai fini della qualità del prodotto, la corretta riferibilità delle grandezze (pressione e flusso gassoso) al sistema SI.

W. Bich
La "Guida all'espressione dell'incertezza di misura": a che punto stiamo?
Atti del V Congresso Metrologia & Qualità, Torino, marzo 2007 (cd rom).

Questo articolo esamina la presente situazione della "Guida all'espressione dell'incertezza di misura" e ne delinea gli sviluppi futuri. Dopo un breve excursus storico, si presenta l'attività del Joint Committee for Guides in Metrology, Working Group 1, che ha l'incarico di promuovere la diffusione della GUM e di preparare quei documenti di supporto che si ritengano necessari. Vengono menzionati e brevemente illustrati alcuni dei documenti in preparazione.

G. Buonanno, G. Ficco, G. Giovinco, G. Molinar Min Beciet
Il ruolo dell'INRIM e dell'Università di Cassino nello sviluppo di modelli numerici per l'analisi di bilance di pressione
Atti del V Congresso Metrologia & Qualità, Torino, marzo 2007 (cd rom).

Negli ultimi anni è notevolmente aumentato l'interesse scientifico nell'utilizzo di metodi numerici finalizzati alla caratterizzazione e/o progettazione di bilance di pressione. Il diffondersi di tali tecniche è stato reso possibile dalla notevole potenzialità e flessibilità dei metodi, in particolare del Metodo agli Elementi Finiti (FEM). Diversi aspetti riguardanti in particolare il coefficiente delle distorsioni elastiche e la velocità di discesa del pistone sono stati analizzati dagli autori: l'influenza del profilo dimensionale del gioco, l'utilizzo del metodo nella progettazione di unità complesse e innovative, l'utilizzo di metodi alternativi semplificati, il modello fluidodinamico basato sull'equazione di Stokes ed infine la stima dell'incertezza.Nel presente articolo gli autori illustreranno il metodo sviluppato focalizzando l'attenzione sui miglioramenti apportati nel corso degli anni. Verrà inoltre presentato uno stato dell'arte sui metodi numerici sviluppati per l'analisi delle bilance di pressione negli ultimi anni.

P. Buonadonna, F. Concas, G. Dionoro, P. Pedone, D. Romano
Model based sampling plans for CMM inspection of form tolerances
Atti dell' 8º Convegno Nazionale A.I.Te.M. (Associazione Italiana Tecnologia Meccanica), pp. 85-88, Montecatini Terme, settembre 2007.

We propose a method for designing CMM inspection plans of small size for use in form error evaluation of parts from batch or mass production. The method exploits a priori information coming from large sample inspection of one or a few parts of the lot. It is based on a regression model fitted to the large sample. The model is used twice. First, it provides the dominant pattern of the surface. Then, the deviations from the model that are relevant to form error are captured by weighting the points of the convex-hull of the large sample with the regression residuals. Basing on two case studies we show that the method provides enough accurate estimates of straightness and flatness and, differently from sample-based methods, is also able to make the user aware of possible outlier parts during inspection.

M. Caravaggio, G. Abate, G. Molinar Min Beciet, P. De Maria
Bilance di pressione per applicazioni industriali fino a 120 Mpa
Atti del V Congresso Metrologia & Qualità, Torino, marzo 2007 (cd rom).

Nell'ambito di una collaborazione iniziata nel 2005 fra la ditta Scandura, Milano e l'I.N.RI.M., Torino si è avviata la progettazione e costruzione di una serie di bilance di pressione in mezzo liquido fino a 120 MPa ed in mezzo gassoso fino a 12 MPa. Nell'articolo viene descritto in modo dettagliato il progetto costruttivo della bilancia di pressione in mezzo liquido fino a 120 MPa. Vengono descritte con particolare attenzione le scelte effettuate per la progettazione e costruzione dell'accoppiamento pistone-cilindro (in carburo di tungsteno) ed il progetto complessivo al fine di disporre di una bilancia di pressione molto compatta, facilmente trasportabile e dotata di tutti gli opportuni sensori di misura per la correzione degli errori dovuti alle principali variabili di influenza. Si sono determinate sperimentalmente le principali caratteristiche metrologiche di alcuni pistoni-cilindri e si sono ottenuti interessanti risultati che sono ampiamente riportati nell'articolo. L'incertezza estesa (k=2) della misura di pressione con la bilancia di pressione in oggetto è sempre compresa fra 50 e 100 ppm (1 ppm = 10^-6).

G. D'Agostino, S. Desogus, A. Germak, C. Origlia, D. Quagliotti
L'accelerazione di gravità in Metrologia, Geofisica e Geodesia: utilizzo e riferibilità della misura
Atti del V Congresso Metrologia && Qualità, Torino, marzo 2007 (cd rom).

L'accelerazione di gravità g è spesso considerata una costante fisica. Essa è in realtà una quantità geofisica che varia rispetto alla posizione sulla Terra e al tempo nello stesso luogo. In Metrologia il valore assoluto dell'accelerazione di gravità locale è tradizionalmente utilizzato nella realizzazione dell'unità di forza e di quelle unità SI da essa derivate (coppia, durezza e pressione). Recentemente la stima di g ha anche assunto un ruolo importante nella determinazione delle costanti fondamentali, come la costante di Planck, su cui si basa una possibile ridefinizione del kilogrammo. In alcuni settori della Geofisica e della Geodesia, la misura delle variazioni temporali di g è correlata a fenomeni geodinamici. Questi possono essere molto lenti e di piccola entità oppure veloci ed intensi secondo la dinamicità del sito di misura. Nel 2005 è stato reso operativo il nuovo gravimetro assoluto trasportabile IMGC-02, sviluppato nei laboratori dell'Istituto Nazionale di Ricerca Metrologica INRiM. L'IMGC-02 adotta il metodo balistico, riconosciuto come metodo primario per la misura dell'accelerazione di gravità. L'IMGC-02 è stato utilizzato sia nel laboratorio Forze dell'INRiM, sia in una campagna di misure commissionate dall'Istituto Nazionale di Geofisica e Vulcanologia (INGV) nell'area dei Colli Albani. Si descrivono i risultati ottenuti in queste misurazioni e quelli ottenuti nel Confronto Internazionale tra Gravimetri Assoluti, organizzato al Bureau Internationale des Poids et Mesures (BIPM) nel settembre 2005.

C. Del Negro, A. Germak, F. Greco, C. Origlia, A. Sicali, G. Budetta, G. D'Agostino, S. Desogus, D. Quagliotti, R. Napoli
Integration between microgravity observations routinely performed on Etna and absolute measuremenst acquired by the IMGC-02 transportable absolute gravimeter
Atti 26º Convegno Nazionale del Gruppo Nazionale di Geofisica della Terra Solida (GNGTS), pp. 551-552, novembre 2007.

A. Germak, G. D'Agostino, G. Barbato
IMGC-02: caratterizzazione metrologica di un nuovo gravimetro assoluto trasportabile
Atti del VII Congresso Nazionale di Misure Meccaniche e Termiche (MMT07), pp. 1-11, Folgaria (Tn - Italy), Ed. Università degli studi di Trento, settembre 2007.

In questi ultimi trenta anni lo sviluppo dei gravimetri balistici assoluti trasportabili ha migliorato sostanzialmente la capacità di misurare l'accelerazione di gravità locale g (accelerazione di caduta libera). L'applicazione di nuovi progressi tecnologici e lo studio approfondito dei fenomeni fisici che influenzano la misura assoluta di g hanno permesso miglioramenti significativi nell'incertezza, ora dichiarata ad alcune parti su 10⁹. Per il futuro si pensa ancora di poter ridurre la dimensione, il peso e i costi, e contemporaneamente, di poter aumentare la semplicità operativa degli strumenti migliorando comunque l'incertezza di misura. Tuttavia occorre notare che ancora oggi mancano informazioni specifiche riguardo la valutazione dell'incertezza nelle misure di g, fondamentali per il confronto delle misure realizzate da differenti strumenti. In particolare, secondo la nostra conoscenza, manca un'analisi completa effettuata secondo la guida all'espressione dell'incertezza nelle misure (ISO-GUM). Lo scopo di questo lavoro è evidenziare i parametri di influenza nella misura con un esempio della caratterizzazione metrologica di un gravimetro assoluto trasportabile secondo la guida di riferimento ISO-GUM. Come esempio è utilizzato il gravimetro assoluto trasportabile IMGC-02, unico nel mondo, a questo livello di accuratezza, che usa il metodo di analisi di entrambe le fasi di salita e discesa di un grave. In particolare presentiamo: la descrizione del nuovo gravimetro assoluto trasportabile IMGC-02 realizzato all'Istituto nazionale di Ricerca Metrologica (INRIM); la lista completa dei fattori di influenza della misura (caratteristica dello strumento e del luogo di osservazione), specialmente riguardo alla valutazione degli effetti dovuti ai fattori di influenza, come quelli dovuti all'equilibratura del retroriflettore, alla verticalità del fascio laser e all'accelerazione di Coriolis; il calcolo dell'incertezza con le tabelle di incertezza di misura e dello strumento e alcuni risultati sperimentali che mostrano la ripetibilità e la riproducibilità di misura tipiche dell'IMGC-02.

S. Guzzetti, F. Pennecchi, B. Zingaro, A. Ferrari, A. Faravelli, L. Viberti, A. M. Ferrari
Checking diagnosis by telepathology: a statistical analysis of one year of experience in remote second opinion on pap smears performed in a surgical pathology department in Zambia
IV Congresso Nazionale di Anatomia Patologica, SIPAPEC-IAP, Milano (Italy), ottobre 2007.

S. Lorefice, A. Malengo
La misura della viscosità con i viscosimetri a capillare
Atti del V Congresso Metrologia & Qualità, Torino, marzo 2007 (cd rom).

I viscosimetri a capillare di vetro sono gli strumenti più utilizzati in ambito industriale e in quello scientifico per misurare la viscosità cinematica, assoluta (dinamica) o relativa di liquidi newtoniani. Costruttivamente sono strumenti semplici, caratterizzati da un tubo capillare calibrato nel quale un liquido fluisce per effetto di uno sforzo generato dalla gravità (viscosimetri a caduta libera). Il metodo di misura può sembrare relativamente semplice, ma nella realtà la misura è resa complessa dai molti fattori che influiscono sulla sua accuratezza. Il principio di misura ed i maggiori fattori di influenza che devono essere considerati per precise ed accurate misure di viscosità cinematica sono trattati nel seguito del presente lavoro.

W. Pasin, G. B. Picotto, M. Pisani, A. Sacconi
Taratura di attuatori a risoluzione nanometrica
Atti del V Congresso Metrologia & Qualità, Torino, marzo 2007 (cd rom).

G. B. Picotto, M. Pometto
Taratura di campioni a gradino e a solco
Atti del V Congresso Metrologia & Qualità, Torino, marzo 2007 (cd rom).

G. Bongiovanni, G. Ficco, G. Molinar, P. Vigo
Il nuovo approccio della MID sugli strumenti di misura e l'ICT al servizio della metrologia legale
Atti del V Congresso Metrologia & Qualità, Torino, marzo 2007 (cd rom).

La recente pubblicazione della Direttiva 2004/22/EC del Parlamento Europeo e del Consiglio sugli strumenti di misura, nota come Direttiva MID (pubblicata il 31/03/2004, e che dovrà essere recepita dagli stati membri entro il 2006) rappresenta il primo importante sforzo di armonizzazione e di modernizzazione del settore della Metrologia Legale. Il recepimento dei principi della MID consentirà di limitare, sia a livello nazionale che internazionale, la proliferazione di leggi, norme e decreti, di procedure e raccomandazioni tecniche, che oggi rallenta i processi della metrologia legale e che determina oggettive difficoltà per tutti gli attori del sistema. L'Information and Communication Technoplogy (ICT) offre oggi numerose opportunità di progresso per l'intero sistema della metrologia legale e potrà consentire la semplificazione dei processi ed il miglioramento dell'efficacia e della qualità del servizio, garantendo allo stesso tempo protezione e sicurezza dei dati, accessibilità delle informazioni e trasparenza delle procedure.

Books

G. Buonanno, G. Ficco, G. Giovinco, G. Molinar Min Beciet
Ten years of experience in modelling pressure balances in liquid media up to few GPa
G. Molinar Min Beciet and G. Buonanno Editor, Collana scientifica della Facoltà di Ingegneria_02; Università di Cassino, Febbraio 2007, pp. 182, ISBN:978-88-8317-037-9, available for free on the web at: http://cassino.adacto.it/sba/modelling_pressure.cfm

IMGC-CNR, now INRIM, started in 1988 the development of analytical methods associated with FORTRAN software with the iterative aim of calculating the pressure distribution in piston-cylinder clearances and the main metrological characteristics of piston-cylinder units. In 1996 the cooperation between IMGC-CNR and the University of Cassino started due to the latter vast experience in handling finite element methods (FEM). Having been engaged in these studies for more than 10 years, we decided to write down our experiences, in order to be able to contribute to the scientific debate on the problems of the uncertainty of modern pressure balances. We decided to write this book in a open way, making it accessible to all our colleagues on internet and publishing it for free distribution, as we are primarily interested to gain experience all together. The following main topics are reported in the chapters of the book: generalities on the pressure scale, description of pressure balances for pressure measurements in liquids up to 3 GPa, derivation of the measurement uncertainty for pressure balances, theoretical methods used to derive the effective area Ae and the pressure distortion coefficient l with the presentation of the iterative numerical methods used, some important aspects of the finite element methods (FEM), details of experiences gained within EUROMET Project 463 and of the EUROMET Project 740 for the calculation of A₀, the collaborations with different international Institutes and Companies.

Technical Reports

M. Bergoglio
Comparison of pressure measurements from 10 MPa to 70 MPa using a transfer standard pressure transducer
INRIM Technical Report no. 58, May 2007.

M. Bergoglio, D. Mari
INRIM results for CCM key comparison CCM.P-K-12 for He leak rates
INRIM Technical Report no. 69, October 2007.

In the month of February 2007 a CCM.P-K-12 key comparison of flow rates of helium leak artefacts into vacuum started to test the calibration measurement capabilities for leak rates and to compare the pertinent national standards. The aim of this comparison is to introduce the CMC entries for leak rates in the BIPM date base. This report details the followed procedure and the results of measurements made at I.N.RI.M. in March 2007.

P. A. Carroll, D. Mari, J. C. Greenwood , G. Raiteri, G. Rumiano
Calibration of two spinning rotor gauge as a bilateral comparison between NPL and I.N.RI.M. in the range 3·10^-4 Pa to 9·10^-2 Pa
NPL report DEPC-EM 015, February 2007.

This report details measurements made at NPL and INRIM between July and August 2005, which form a comparison to determine the degree of equivalence of absolute pressure standards at these National Metrology Institutes.

G. D'Agostino, A. Germak
Stima dell' equazione caratteristica della macchina a moltiplicazione a leva MCF03-600kN della Cooperativa Bilanciai
Rapporto Tecnico INRIM n. 53, aprile 2007.

Nell'ambito del contratto stipulato tra la Cooperativa Bilanciai e l'Istituto Nazionale di Ricerca Metrologica (INRIM) sono state condotte delle prove sperimentali al fine di caratterizzare la macchina campione di forza a moltiplicazione a leva MCF03-600kN in dotazione alla Cooperativa Bilanciai. In particolare è stata calcolata l'equazione caratteristica della sopraccitata macchina tramite un confronto con la macchina a pesi diretti Galdabini da 1 MN in dotazione all'INRIM utilizzando campioni di trasferimento di elevata qualità. In aggiunta, sulla base di tale caratterizzazione, si riportano in appendice alcune considerazioni circa il possibile utilizzo della MCF03-600kN nella caratterizzazione di celle di carico per le misure di massa.

G. D'Agostino, S. Desogus, A. Germak, C. Origlia, D. Quagliotti
Absolute measurements of the free-fall acceleration g in Santangelo Romano Palestrina and Castel Gandolfo (Italy)
INRIM Technical Report no. 59, June 2007.

The work hereafter described was carried out on May 23-30, 2007 by the Istituto Nazionale di Ricerca Metrologica (INRIM) for the Istituto Nazionale di Geofisica e Vulcanologia (INGV) - Centro Nazionale Terremoti and Osservatorio Vesuviano. The experimental results of absolute measurements of the free-fall acceleration g carried out at Santangelo Romano, Palestrina and Castel Gandolfo are reported. Gravity measurements were performed with the new transportable absolute gravimeter IMGC-02.

G. D'Agostino, S. Desogus, A. Germak, C. Origlia, D. Quagliotti
Absolute measurements of the free-fall acceleration g in Pantelleria (Italy)
INRIM Technical Report no. 76, June 2007.

The work hereafter described was carried out on June 23-36, 2007 by the Istituto Nazionale di Ricerca Metrologica (INRIM) for the Istituto Nazionale di Geofisica e Vulcanologia (INGV) - Centro Nazionale Terremoti and Osservatorio Vesuviano. The experimental results of absolute measurements of the free-fall acceleration g carried out in Pantelleria are reported. Gravity measurements were performed with the new transportable absolute gravimeter IMGC-02.

G. D'Agostino, S. Desogus, A. Germak, C. Origlia, D. Quagliotti
Absolute measurements of the free-fall acceleration g in Catania and Etna volcano (Italy)
INRIM Technical Report no. 73, Nov. 2007.

The work hereafter described was carried out on June and July 2007 by the Istituto Nazionale di Ricerca Metrologica (INRIM) for the Istituto Nazionale di Geofisica e Vulcanologia (INGV) - Catania Section. The experimental results of absolute measurements of the free-fall acceleration g carried out at Catania and Etna Volcano are reported. Gravity measurements were performed with the new transportable absolute gravimeter IMGC-02.

A. Germak, C. Origlia
Metrological characterization of the Primary Hardness Standard Machine and Gal-Vision Measuring System realised by LTF for NPL (India)
INRIM Technical Report no. 54, April 2007.

The work consists in the metrological characterization of the Primary Hardness Standard Machine (PHS Machine) and Gal-Vision Measuring System realized by LTF S.p.A. for the National Physical Laboratory (NPL), in India. The work described in the report was carried out in January and February 2007, by the Istituto Nazionale di Ricerca Metrologica (INRIM) of Italy (formerly Istituto di Metrologia "G. Colonnetti" (IMGC) of the National Research Council (CNR)) at LTF laboratory in Antegnate (BG), Italy. PHS Machine has been realized by LTF with the INRIM know-how. The Gal-Vision measuring system derives from the measuring system developed in IMGC, now used in INRIM hardness laboratory, based on the CNR patent algorithm. The metrological characterizations consists in the direct and indirect verification of the PHS machine; in the direct verification, the main verified parameters are the forces generated by the PHS machine, the depth measuring system and the geometry of the indenters. The indirect verification consists in the comparison of the whole performances of machine and measuring system (including indenter performances with the so called "National Indenters") and in the comparison of the hardness scales generated by the PHS machine with the national scales maintained by INRIM. The results have been compared with the technical specifications of the PHS machine to verify the quality of the LTF construction.

A. Germak, C. Origlia
Comparison of Hardness Scales between the INRIM Primary Hardness Standard Machine and the AFFRI Master Rockwell and Vickers Reference Hardness Standard Machines for SIMT (Shanghai-China)
INRIM Technical Report no. 55, April 2007.

The work consists in the comparison of Vickers, Brinell and Rockwell Hardness Scales realized by the INRIM Primary Hardness Standard Machine (PHS Machine) and the Affri Master Rock and Affri Master Vick Reference Hardness Standard Machines (RHS Machines) for SIMT, Shanghai, China. The work described in the report was carried out in February and March 2007, by the Istituto Nazionale di Ricerca Metrologica (INRIM) of Italy (formerly Istituto di Metrologia "G. Colonnetti" (IMGC) of the National Research Council (CNR)) at AFFRI Laboratory in Induno Olona (VA), Italy. The comparison of the hardness scales generated by the RHS machines with the national scales maintained by INRIM gives an indication of the whole performances of RHS machines and measuring system.

A. Malengo, S. Pettorruso, A. Capelli
Misura accurata della posizione del centro di massa di un corpo mediante pesata
Rapporto Tecnico INRIM n. 72, Nov. 2007.

La posizione del centro di massa di un corpo può essere determinata attraverso il metodo che utilizza un ponte di pesata. Utilizzando questa tecnica è stato progettato e realizzato un sistema di misura costituito da una bilancia con risoluzione di 1 mg e da un ponte di pesata. Nell'articolo sono descritte due procedure di misurazione, le quali permettono di calcolare, rispettivamente, l'altezza del centro di massa e lo scostamento della posizione del centro di massa rispetto al centro di simmetria geometrico del corpo. Sono inoltre presentati il metodo adottato per la taratura del sistema e l'analisi della valutazione dell'incertezza di misura. L'incertezza tipo valutata per campioni di circa 1 kg (altezza di circa 68 mm) è risultata entro alcuni micrometri.

G. Mana, E. Massa
Relazione di avanzamento attività progetto D64 dispositivo di traslazione con risoluzione sub-nanometrica. Regione Piemonte - bando ricerca scientifica applicata 2004
Rapporto Tecnico INRIM n. 64, settembre 2007.

L'obiettivo del progetto è realizzare un sistema di traslazione del cristallo mobile di un interferometro a raggi X a scansione estendendo il campo di lavoro dell'interferometro ad alcuni centimetri e, quindi, migliorando la risoluzione e accuratezza dello strumento. La motivazione è essenzialmente scientifica: nell'ambito di una collaborazione per lo sviluppo delle tecnologie necessarie a ridefinire l'unità di massa contando il numero di atomi in un cristallo di ²⁸Si, occorre misurare la distanza interatomica degli atomi nel cristallo mediante un interferometro doppio ottico e X capace di risoluzione e accuratezza fino alla nona cifra significativa. Nel corso del progetto è emersa possibilità di utilizzare l'interferometria X a lungo campo per la misura del passo reticolare di un cristallo da utilizzare per la determinazione assoluta della frequenza della radiazione gamma emessa in transizioni nucleari e, quindi, del difetto di massa, ad esse associato. La motivazione scientifica del progetto non esclude ricadute di interesse applicativo nel campo dell'ingegneria di precisione, della nanometrologia e dei sistemi di posizionamento e manipolazione con risoluzione alla scala delle dimensioni atomiche.

G. Mana, E. Massa
Quantum Standard for Noise Measurements
INRIM Technical Report no. 71, Nov. 2007.

The measurement of the Boltzmann constant k_B, or, equivalently, of the thermodynamic temperature via noise thermometry, requires a noise source whose power spectrum density is calculable from first principles to within at least 10^-6 relative accuracy. The operation of such a reference cannot rely on thermodynamics, otherwise the value of k_B, whose measurement has been targeted, will be part of its model. Consequently, it must rely on quantum mechanics. Additionally, since the effect of the environmental thermal bath must be less than one part per million and since, at room temperature, the equilibrium energy is k_B, \Theta =25$ meV, the underlying physical process must operate at an energy scale of at least 0.1 MeV. Accordingly, it will be discussed a current generator collecting high energy particles from a radioactive material. The basic assumption is that the flux of charged particles is white, at least on a given frequency band, and obeys the Poisson statistic.

C. Marinari
Evaluation of the main metrological characteristics of the CENAM 150 kN deadweight force standard machine by using the INRIM 100 kN six-component dynamometer
INRIM Technical Report no. 62, June 2007.

F. Pollastri
AVC, Application View Controller, User Manual
INRIM Technical Report no. 70, October 2007.

AVC, the Application View Controller is a multiplatform, fully automatic, live connection among graphical interface widgets and application variables for the python language. AVC supports in a uniform way the most popular widget toolkits: GTK, Qt3, Qt4, Tk, wxWidgets. AVC is a normal python module that can be imported by any python application. Graphical User Interfaces (GUIs) are the easy way to input data to an application software and to view the data produced by the application. The management of data exchanges between the GUI and the application is a central problem in GUI programming, it absorbs a relevant part of the programming effort. AVC makes the programming of this data exchanges very easy. AVC is a fully transparent and automatic connection between the values displayed and entered by GUI widgets and the variables of an application using the GUI. The connection is bidirectional. If the application sets a new value into a connected variable, AVC copies the new value into all the widgets connected to the variable. If a new value is entered by a widget, AVC copies the new value into all other widgets connected the variable, into the variable and optionally notifies the change to the application. The connections are autogenerated by looking for matching names between widget names and variable names.