Istituto Nazionale di Ricerca Metrologica
METRICA Archivio istituzionale della ricerca - INRIMNot a member yet
8322 research outputs found
Sort by
Improvement of the INRiM Calibration Capabilities for Lightning Impulse Voltages From 200 to 600 kV
Full text linkIn this paper, an improvement of the calibration measurement capabilities (CMCs) of the Istituto Nazionale di Ricerca Metrologica (INRiM) for measurements of Lightning impulse (LI) voltages from 200 kV to 600 kV, is proposed. This improvement is the result of a more detailed characterization of the INRiM measurement system for LI measurements. The INRiM LI measurements of the most critical waveforms at voltages up to 600 kV for the EURAMET.EM-S42 comparison were submitted to a refinement with a discrete deconvolution method. The comparison results were then recalculated by inserting the INRiM measurements, both with and without deconvolution, (the latter for less critical waveforms) and the updated uncertainties. The INRiM measurements after recalculation were still in agreement with the comparison reference value, even for short impulses (0.84 μs), where the size of the used divider was not optimal. The recalculation did not affect the degrees of equivalence of the other participants and the consistency of the comparison. The new INRiM uncertainties range from 0.5 % of Ut (test voltage) for the long impulse at 600 kV to 2 % of T1 (front time of the impulse) for the short impulse at 400 kV and 600 kV. A validation of both the new uncertainties and the selected discrete application of deconvolution is also proposed, together with a verification of the compliance of the INRIM measurement system up to 600 kV with the requirements of a reference system
Verifica della linearità dello shunt per forti correnti di corto circuito fino a 230 kA
Full text linkThis technical report describes the study of the linearity of the measurement system used at INRiM for the calibration of short-circuit currents. The verification was carried out by comparison with an intrinsically linear measurement system based on a Rogowski coil. The characteristics of the INRiM measurement system are reported, particularly those of the shunt, as well as a description of the measurement system used to verify the linearity of the INRiM system. The comparative measurements between the systems are analyzed, assessing the linearity of the INRiM system both for the peak current and for the Joule integral, along with the uncertainties of these assessments. Finally, the overall uncertainties of the INRiM system were reviewed up to 170 kA and up to 230 kA, resulting respectively 4.2×10−3 and 5.6×10−3 while the uncertainty of the Joule integral increases to 3.4×10−2. As a result of the work carried out, it is considered feasible to extend the INRiM CMC for the calibration of short-circuit currents up to 230 kA with the obtained uncertainties
Using triangulation method to address regression problems for measurements of ultra-high electrical resistance
No full textThe triangulation is widely applied in research and surveying and its application in metrology can support the choice of extrapolating measurement values through regression models, a practice that still encounters opposition among metrologists. Triangulation offers an approach to improve the accuracy and reliability of regressions by allowing for the verification of their results against independent measurement techniques or data sources. In a general, triangulation involves using independent sources or methods to validate a conclusion or measurement. Within metrology, this means to compare measurements obtained from different instruments or techniques to minimize bias [1] and increase the overall confidence in the final measurement result. Our work focuses on extending the capabilities of high resistance measurement systems, specifically, applying the principles of metrological triangulation. This approach allows us to extend reliably the measurement ranges of these systems, particularly in areas where their performance is limited. First application of the method was on the dual source high resistance bridge (DSB
Electrical signalling in tomato — Oidium neolycopersici pathosystem for detection of powdery mildew
No full textPlants are subjected to a plethora of biotic stresses caused by various pathogens; among them, fungal pathogens represent the most destructive ones. In order to preserve the health status of plants, especially under the influence of climate change, the need to develop new sustainable, inexpensive, in-field and non-destructive diagnostic methods for plant pathogens is of great importance. In this direction, spectroscopic and molecular methods have made progress, while others, such as electrical diagnostic methods are still in the early stages of development. In this work, electrical signals in tomato plants infected with the fungal pathogen Oidium neolycopersici, the causative agent of powdery mildew, were measured. Differences in electrical responses were observed between healthy and infected plants during the entire monitoring period, and infected plants showed overall lower values of the electrical potential in comparison with healthy plants. Measurement of electrical potential allowed the successful differentiation between infected and healthy plants before the onset of symptoms (3.2 days in advance). A significant difference in electrical signals was obtained not only between infected and healthy plants, but also concerning the growing substrate: A stronger electrical potential was measured in plants grown in the peat-based substrate compared to those cultivated in the water substrate allowing a 97.5% discrimination. Based on the results of this study, measurements of electrical signals may become the basis for an alternative non-destructive diagnosis of tomato powdery mildew and other plant diseases. With the possibility of directly applying the technique in the field followed by remote monitoring of electrical signals, it may become useful for supporting timely disease control
Development of control programs for automatic calibration of roughness and step standards
No full text
An efficient computational model for single-molecule optoelectronic devices
No full textThe growing interest in tuning the conduction properties of single-molecule junctions has drawn attention to studying their interaction with incident electromagnetic fields. The theoretical complexity of this problem necessitates the use of nonequilibrium statistical mechanics combined with quantum electrodynamics, leading to extremely time-consuming simulations. In this work, we propose a computationally efficient algorithm, which combines EE-BESD—an efficient and effective simulator of current–voltage characteristics in dark conditions—with approximated models for light interaction, specifically the Tien-Gordon and Floquet models. We validate EE-BESD-PAT through comparison with ab initio calculations and experimental data from the literature. Our computational model demonstrates good agreement with both experimental and density functional theory calculations, demonstrating that the proposed method is a promising computationally efficient tool without sacrificing accuracy
Sensor network metrology: Current state and future directions
Full text linkThis article investigates the essential role of sensor network metrology in advancing the reliability and adaptability of sensor networks through a review of the state of the art and expected trends in this field. Addressing the challenges of harmonized metrological approaches, it outlines a future roadmap for the metrological assessment of real-world non-static distributed sensor networks and underlines the importance of joint efforts for a sustainable and reliable future
Metrological approach for permafrost temperature measurements
Full text linkPermafrost degradation is a growing direct impact of climate change. Detecting permafrost shrinkage, in terms of extension, depth reduction and active layer shift is fundamental to capture the magnitude of trends and address actions and warnings. Temperature profiles in permafrost allow direct understanding of the status of the frozen ground layer and its evolution in time. The Sommeiller Pass permafrost monitoring station, at about 3000 m of elevation, is the key site of the regional network installed in 2009 during the European Project “PermaNET” in the Piedmont Alps (NW Italy). The station consists of three vertical boreholes with different characteristics, equipped with a total of 36 thermistors distributed in three different chains. The collected raw data shows a degradation of the permafrost base at approximately 60 m of depth since 2014, corresponding to about 0.03 °C/yr. In order to verify and better quantify this potential degradation, three on-site sensor calibration campaigns were carried out to understand the reliability of these measurements. By repeating calibrations in different years, two key results have been achieved: the profiles have been corrected for errors and the re-calibration allowed to distinguish the effective change of permafrost temperatures during the years, from possible drifts of the sensors, which can be of the same order of magnitude of the investigated thermal change. The warming of permafrost base at a depth of ∼ 60 m has been confirmed, with a rate of (4.2 ± 0.5)∙10−2 °C/yr. This paper reports the implementation and installation of the on-site metrology laboratory, the dedicated calibration procedure adopted, the calibration results and the resulting adjusted data, profiles and their evolution with time. It is intended as a further contribution to the ongoing studies and definition of best practices, to improve data traceability and comparability, as prescribed by the World Meteorological Organization Global Cryosphere Watch programme
Optimizing resazurin-based viability assays for P-MSC/TER308 cell line to enhance results reliability
Full text linkObjective: The results of this research contribute to the LifeSaver project, which focuses on reducing neonatal and infant mortality resulting from preterm births. The project aims to create an in vitro system simulating prenatal conditions to screen and analyze chemicals and pharmaceuticals, establishing scientifically justified regulations for their use during pregnancy. Because several papers have recently identified data inconsistencies in pre-clinical studies, a key part of the project involves optimizing cellular cytotoxicity assays to enhance the reliability of pharmacological and toxicity screening for drugs and environmental contaminants. Results: The resazurin-based viability assay was chosen as the primary method due to its widespread adoption and simplicity in assessing drug cytotoxicity. This work describes the optimization of the resazurin-based viability assay on the P-MSC/TERT308 cell line, a placenta-derived mesenchymal stem cell used within the LifeSaver project. By applying our previously described and validated Standard Operating Procedure, we fine-tuned experimental parameters, consistently obtaining reliable results with measurement uncertainty of less than 10%