Sensitivity of the Drop Length in a Rise and Fall Absolute Gravimeter: Simulation and Data from the IMGC-02 Instrument Operating in Different Measurement Sites

In ballistic absolute gravimeters, the length of the analyzed trajectory of the falling object plays a crucial role in the accuracy and the precision of the determination of the gravity value. The effect is generated by different known and unknown sources. They depend both on the instrument setup, e.g. mechanical systems or fringe signal processing, and the measurement site, namely the stiffness of the floor. The dominant aspect concerns the recoil which appears at the start of the drop. In the case of rise and fall method, as for the IMGC-02 apparatus, the magnitude of such recoil is higher with a respect to the freefall one. A detailed analysis of the sensitivity of the drop length for this absolute gravimeter was never done before. The goal of the study is to evaluate how the variation of drop length can affect the measurement of the free fall acceleration, in order to achieve best solution to minimize the perturbation without reduce the resolution. The solution must be found as a function of the different measurement site and its associated uncertainty were evaluated

Verification of Knoop indenters with Gal-Indent optical system

Le normative internazionali ISO 4545-2 e 4545-3 per i test di durezza Knoop richiedono la verifica geometrica dei penetratori. Il laboratorio di durezza INRiM, in collaborazione con la Galileo-LTF®, ha sviluppato uno specifico sistema ottico di misurazione(commercializzato da Galileo-LTF® come Gal-Indent) , utilizzato per la verifica dei penetratori Vickers. Questo sistema è in grado di misurare i due angoli al vertice tra due facce opposte, i quattro angoli della base quadrangolare e l'angolo tra l'asse della piramide di diamante e l'asse del codolo del penetratore. Usando le misure degli angoli al vertice e della base come input di un appropriato modello geometrico, gli angoli al vertice tra spigoli opposti di penetratori Knoop, nominalmente di 172.5° e 130°, e l'angolo tra l'asse della piramide di diamante e l'asse del supporto del penetratore, nominalmente di 0°, possono essere verificati con un'incertezza estesa di 0.05°, come richiesto dalle normative. Il confronto tra le misure sperimentali eseguite con questo metodo su tre diversi penetratori Knoop, precedentemente verificati da un laboratorio accreditato tedesco, mostrano risultati compatibili, in termini di errore normalizzato.ISO 4545-2 and 4545-3 of Knoop hardness tests require the geometrical verification of the indenters. INRiM hardness laboratory, in cooperation with Galileo-LTF® has developed a specific optical measuring system (commercialized by Galileo-LTF® as Gal-Indent) which is addressed for the verification of Vickers indenters. This system is able to measure the two vertex angles between two opposite faces, the four angles of the quadrilateral base and the angle between the axis of the diamond pyramid and the axis of the indenter holder. Using the measured quantities of the vertex and base angles as inputs of a suitable geometrical model, the angles from the opposite edges at the vertex of Knoop indenters, nominally 172.5° and 130°, and the angle between the axis of the diamond pyramid and the axis of the indenter holder, nominally 0°, can be verified with an expanded uncertainty of 0.05°, as required by the relevant Standard. Comparison of experimental measurements performed on three different Knoop indenters, previously verified by a German accredited laboratory, shows compatible results in terms of normalized error

Self-calibration of the 1 MN deadweight force standard machine at INRiM

open4noThe INRiM 1 MN deadweight force standard machine (DFSM) was installed in 1995. It adopts a binary sequence of ten weights whose combinations generate forces up to 1 MN. The advantage of this system lies in the self-calibration of its weights. The procedure is based on the comparison between two forces generated by a single weight and by a group of smaller weights, nominally equal. After 25 years, a verification of the DFSM was performed. Results are within the declared CMC limits, i.e. a relative expanded uncertainty of 2 × 10-5.openPrato, A.; Mazzoleni, F.; Facello, A.; Germak, A.Prato, A.; Mazzoleni, F.; Facello, A.; Germak, A

Colours and aircraft interiors. Design scenarios for a regional aircraft cabin.

The paper aims to investigate the use of colour and its perception within the cabin of a regional aircraft used for short distances and it is divided into two parts. The first part presents an analysis of the literature and the state of the art on the use of colour both within the aeronautical sector and in comparable sectors, such as that of interior architecture, where over the last few decades researchers formulated different theories of approach. The case studies examined show that, today, the choice of using colour is mainly based on marketing factors linked to the corporate branding of airlines, with a lack of sensitivity to human factors. The literature on colour, on the other hand, suggests that the different tones of colour have a strong impact from a physiological and psychological point of view, factors that must be taken into consideration to improve the experience of wellbeing on board, defining a framework of requirements. The chromatic hypotheses were, then, examined and compared through a preliminary perceptual test conducted on a sample of 20 subjects aimed at evaluating and defining guidelines for approaching the colour project. The objective of the guidelines is the construction of chromatic design scenarios defining a comfortable environment from the visual point of view and capable not only of generating a pleasant, comfortable travel experience but also a feeling of security and limiting the typical unwanted perceptions related to flight. The paper is part of the dissemination of the H2020 CASTLE project (CAbin Systems design Toward passenger welLbEing)

The extended comfort. Analysing the flight journey through a design-oriented approach.

The study of passengers' comfort on an aircraft is a research field that, has been able to accommodate both quantitative contributions, deriving from disciplines such as ergonomics, and qualitative contributions coming from product design. In recent years, design research has also focused on experiential and perceptive aspects, considering disciplines such as Interaction Design and User Experience. In the first instance, the paper aims to systemize the different design-oriented approaches that generated a complex map based also on the support of visual narration. In the map the flight experience is treated as if it were a service, analysing the entire customer journey to highlight the most critical issues. The methodological steps, based on the analysis of the activities, as well as those based on the optimization of the components, are then integrated into a holistic vision. The system has been created on the basis of case studies drawn from aircraft currently in service and from still embryonic concepts, capable of providing useful categories of analysis. The paper ends with the application of the map to an application study case: the CASTLE project (CAbin Systems design Toward passenger welLbEing)

Bilateral comparison in Rockwell C hardness scale between INRiM and GUM

This bilateral comparison in HRC is conducted in order to confirm the accuracy claimed by National Institute of Metrological Research in Italy (INRiM) and Central Office of Measures in Poland (GUM). Also, this study compares the difference of measurement results between two modernized deadweight-type Rockwell's hardness standard machines (HSMs) from GUM and primary hardness standard machine (PHSM) from INRiM. The hardness blocks of about 20 HRC, 35 HRC, 45 HRC, 50 HRC, 60 HRC and 65 HRC, which all have uniformity less then ±0.4 HRC according to EN ISO 6508-3, were used in this comparison

EURAMET key comparison between INRiM and UME in Vickers hardness scales (HV1 - HV30) - EURAMET.M.H-K1.b and c

This report describes the method and results of a bilateral EURAMET Key Comparison in Vickers hardness scales of two National Metrology Institutes (NMIs) of Italy and Turkey, INRiM and UME, respectively. The Pilot Laboratory (PL) is INRiM in the comparison in which one set of hardness reference blocks with three hardness levels for the Vickers Hardness scales of both HV1 and HV30 was used. The comparison was realized as planned in the Technical Protocol with some delay. The aim of this comparison is to link the UME measurement results to the CCM.H-K1.b.c through the PL (INRiM) as a participant of the CCM key comparison. The measurement results and uncertainty assessments declared by INRiM and UME are in consistency with each other and UME results are also in consistency with the CCM.H-K1.b.c Key Comparison Reference Values (KCRVs). The CCM.H-K1.b.c was realized during 2001 to 2003 to investigate the metrological equivalence of national standards among national metrology institutes (NMIs) within the CCM

Procedura di confronto tra AEP, INRIM e PTB per la taratura della macchina di taratura di forza per confronto da 5 MN del Laboratorio AEP.

During the period from March to June 2015, a comparison between the primary force standard machine of the Istituto Nazionale di Ricerca Metrologica (INRiM) in Turin and Physikalisch-Technische Bundesanstalt (PTB) in Braunschweig (Germy) and the 5 MN calibration force machine for comparison of the accredited calibration Laboratory of AEP Transducers di Cognento (MO), has been carried out. The comparison, carried out according the calibration guide EURAMET cg-4, Version 2.0, following the Traceability Path A, has been used to perform the calibration of the calibration force machines

Evaluating Measurement Uncertainty in Absolute Gravimetry: an Application of the Monte Carlo Method

Absolute gravity measurements are based on the reconstruction of the free-falling motion of a test body in vacuum. In this paper, two large disturbing effects are studied, namely, the non- gravitational accelerations originated by rotation and translation of the flying body. Their contribution to the uncertainty of the free-fall acceleration is evaluated using the method proposed in Supplement 1 to the GUM. The analysis is specifically applied to the IMGC-02 absolute gravimeter, but can be easily extended to other instruments