Istituto Nazionale di Ricerca Metrologica
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Conferma Metrologica di dicembre 2023 e di giugno 2024 del Sistema di misura dei Parametri “S” in connessione 2.4mm nel campo di frequenza da 9 kHz a 3 GHz
No full textIn questo rapporto tecnico si descrivono le operazioni di Conferma Metrologica del Sistema di misura dei Parametri “S” in connessione 2.4mm nel campo di frequenza da 9 kHz a 3 GHz. Il risultato di queste operazioni è la determinazione dell’Indice di Compatibilità che, se ≤ 1 in valore assoluto, valida il sistema di misura INRIM
New Candidate Reference Measurement Procedures for MET CNV Detection and Quantification Using Digital PCR
No full textAnalysis of the influence of velocity and time intervals for total force application in Rockwell hardness test cycles
No full textThe influence of key variables on hardness measurements, namely indenter velocity and geometry, dwell times, applied forces and temperature, has been thoroughly investigated in recent decades. The recent implementation of international definitions for the Rockwell hardness scale has heightened interest in understanding how these factors affect measurement outcomes. While these definitions and associated standards provide guidance on specific parameter ranges, the Rockwell hardness equation does not directly integrate these variables, making it necessary to empirically determine their sensitivity coefficients. This study specifically aims to identify the sensitivity coefficients related to two critical parameters: the velocity at which the final load is applied and the duration over which the force transitions from the preliminary value to the total force value. The analysis encompasses multiple Rockwell hardness scales, including B, C, 45 N, 30 N, and 15 N, across a range of hardness levels to deliver a comprehensive evaluation. Additionally, the influence of the duration of the total force application is evaluated for Rockwell C hardness. To conduct this analysis, we employed a Monte Carlo (MC) method in conjunction with Multiple Linear Regression (MLR) techniques, enabling a systematic simulation and assessment of variability in hardness measurements. The findings closely align with existing literature, thereby reinforcing the robustness and reliability of this study. By clarifying the relationship between these influential factors and hardness measurements, this research provides valuable insights aimed at enhancing the accuracy of Rockwell hardness testing practices
Conferma Metrologica di dicembre 2023 e di giugno 2024 del Sistema di misura dei Parametri “S” in connessione 2.4mm nel campo di frequenza da 50 MHz a 50 GHz
No full textIn questo rapporto tecnico si descrivono le operazioni di Conferma Metrologica del Sistema di misura dei Parametri “S” in connessione 2.4mm nel campo di frequenza da 50 MHz a 50 GHz. Il risultato di queste operazioni è la determinazione dell’Indice di Compatibilità che, se ≤ 1 in valore assoluto, valida il sistema di misura INRIM
A comparative study of static, continuous, and dynamic calibration methods for high-precision low-force strain-gauge transducers
No full textThe ISO 376 standard, which underpins static force calibration procedures, does not adequately address the time- and frequency-dependent effects encountered in real-world applications such as aerospace, automotive, and biomedical testing. This study investigates and compares static, continuous, and dynamic calibration methodologies applied to low-force strain-gauge transducers with capacities ranging from 50 N to 500 N. A 200 N transducer was calibrated using all three methods, while others were tested statically and dynamically. Static calibration yielded consistent sensitivity and low uncertainty across all force levels. Continuous calibration, based on DKD-R 3–9, produced comparable sensitivities but showed increased uncertainty, primarily due to reversibility effects and mechanical coupling imperfections. Dynamic calibration, conducted per DKD-R 3–10 using sinusoidal excitation in the range 10 Hz −100 Hz, revealed a frequency-dependent sensitivity reduction, with Monte Carlo-based regression models used to characterize performance. While results across all methods are broadly compatible within declared uncertainties, significant divergence emerges when uncertainties are reduced to static levels. This raises important questions about the traceability and comparability of force measurements under non-static conditions. The findings underscore the need for further refinement in continuous and dynamic calibration methods to meet the demands of advanced material and structural testing
Painting Roofs White: An Affordable Strategy to Improve Indoor Comfort in African Buildings
No full textCorrugated metal sheets are the most widely used roofing solution in Africa. This low cost solution prevents rain from pouring inside the building, but lacks any thermal insulation and reaches very high temperatures by absorption of solar radiation. A solution to prevent indoor overheating is to paint the outer covering of the roof with white coatings having a high solar reflectance to prevent heating, and a high emissivity to dissipate accumulated heat. The lower temperature of the roof further improves the indoor comfort through the reduction of the thermal radiation from the ceiling. The present study estimates the effectiveness of this solution, through the study case of a factory building located in Rwanda. A simulation model was generated including the geometrical, constructive and operational characteristics of the building. Different roof coatings in use for different periods were characterized in Rwanda, using portable equipment for measuring reflectance in the 380–1700 nm wavelength range and directional emittance in the 1.5–21 μm range. For conventional paints, the thermo-optical parameters range from those of a red roof with solar reflectance (SR) of 0.290 and hemispherical total emittance (HTE) of 0.740 and those of a grey one with SR of 0.045 and HTE of 0.877. Among the new white paints, including both local and European products, the highest SR is 0.887 for a coating with HTE of 0.872. The lowest reflectance (0.647) corresponds to the paint with the highest emittance (0.906) related to a content of siliceous aggregate to improve acoustic performance. The results of energy simulations considering the thermo-optical properties measured in situ show that white paints achieve significant energy savings with respect to conventional ones, allowing, in some cases, to avoid the use of air conditioning altogether to keep the temperature inside the factory below 25 °C in the hottest month
Shaping biomimicry: A standardized protocol for soft materials bulk density measurement supporting tissue-like performance
No full textExtension to 230 kA with uncertainty reduction for calibration of shortcircuit currents at INRiM
No full textThe Istituto Nazionale di Ricerca Metrologica (INRiM) is the only National Metrology Institute
(NMI) holding the Calibration Measurement Capability (CMC) for calibrating short-circuit currents
up to 170 kA under the framework of the Mutual Recognition Arrangement of the Comité
international des poids et mesures (CIPM MRA). This paper presents the extension of this CMC up
to 230 kA and the improvement of the measurement uncertainty of the INRiM system for calibrating
sensors and measurement systems for high short-circuit currents and for the Joule integral. The
extension has been possible by means of a linearity verification of the INRiM system carried out by
comparing it with an intrinsically linear measurement system based on a Rogowski coil. This
comparison allowed the update and refinement of the uncertainty budget, specifically the component
associated with the linearity of the INRiM system, for both the peak current and the Joule integral. An
innovative approach has been adopted by applying a median filter to the voltage measurement of the
Rogowski coil to remove noise. This filter has been integrated into the calibration software for high
short-circuit currents and optimized for the use with Rogowski coils without an integrator.The
uncertainties of the INRiM measurement system have been then reviewed and improved for currents
up to 170 kA and 230 kA, resulting, in relative parts 4.2 × 10−3 and 5.6 ×10−3, respectively.
Consequently, the extension of the INRiM CMC for calibration of short-circuit currents and for
Joule integral up to 230 kA can be considered feasible with the achieved uncertaintie
Ultrafast laser-induced refractive index tuning inside GeSbSNa glasses for mid-IR applications
No full textFemtosecond laser direct writing (FLDW) enables precise, three-dimensional (3D) structuring within transparent materials, offering a versatile platform for integrated photonics. In this work, we investigate the photo-response of sodium-doped GeSbS (GeSbSNa) chalcogenide glasses under femtosecond laser irradiation, a system of interest for mid-infrared (MIR) applications yet largely unexplored. Through quantitative phase microscopy, we extract refractive index changes as a function of composition and laser pulse energy, achieving phase shifts up to 62 radians and refractive index contrasts (Δn) exceeding 0.05—among the highest reported for chalcogenide systems. Raman spectroscopy reveals localized structural reorganizations, notably a transition from corner- to edge-sharing GeS4 tetrahedra, consistent with laser-induced densification. We also evaluate the thermal stability of the modifications via isochronal annealing and compare them with commercial glass benchmarks. Overall, these results provide a quantitative basis for assessing GeSbSNa glasses as prospective materials for MIR photonic integration, particularly in contexts where both high photosensitivity and moderate thermal durability are desirable, even though no specific devices are demonstrated here