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Krzysztof Kubiczek, Paolo Durandetto, Pier Paolo Capra, Claudio Francese, Marco Lanzillotti, Luca Roncaglione, Marian Kampik, Andrea Sosso
Verification of thermal converters by means of a pulsed Josephson standard

Starting from 2019 a new central role is played by quantum standards, owing to the redefined SI [1], where electrical units are directly linked to the fundamental constants e (elementary charge) and h (Planck constant). Thus, metrologists are nowadays trying to extend the astonishing accuracy attainable in dc measurements to ac and beyond, moving from sinusoidal toward quantum calibrations of arbitrary signals. Programmable Josephson Voltage Standards are nowadays capable of fulfilling primary metrology requirements only for signals up to few hundreds Hz. Pulsed Josephson standard are instead capable of generating arbitrary waveforms at higher frequencies, so are generally called Josephson Arbitrary Waveform Standards (JAWS). In particular, the capability of generating high spectral purity signals allows high accuracy measurements of the ac-dc difference of thermal converters. We report in the following about our setup for quantum calibrations of thermal converters, first results obtained and open issues.

Alessandro Cultrera, Luca Callegaro, Danilo Serazio, Norbert Fabricius
Towards new IEC standards for the electrical characterization of graphene

New IEC technical specifications, for the standardized assessment of the sheet resistance RS of monolayer graphene, recently published in June 2023 are here presented. These new standards of the series IEC TS 62607-6-xx describe protocols for the application of the contact methods i) in-line four point probe and ii) van der Pauw. The general IEC context of the main development steps for standards and and example of the scientific experiments used as input for the standard development are also presented.

Bin Deng, Ze-Xin Guan, Dong-Sheng Zhao, Xue-Feng Ma, Ru Jia, Hong-Rui Yan, Hai-Long Xu,Guang-Kun Dong, Fan-Li Kong
Study on Calibration Method for Emergency Lighting and Evacuation Indicating System

The quality inspection department regularly conducts spot checks on the quality issues of the fire emergency lighting and evacuation indication system, and detects the internal power supply voltage, emergency time, charging and discharging voltage, charging and discharging current, and other metrological characteristics of the system to ensure that the metrological characteristics of the system meet the requirements of national standards. However, there is a lack of reliable calibration methods and devices in China. In order to solve the problem of quantity traceability of detection devices for fire emergency lighting and evacuation indication systems, a calibration method for detection devices for fire emergency lighting and evacuation indication systems is studied.

Luca De Vito, Francesco Picariello, Sergio Rapuano, Ioan Tudosa
Characterization of an accurate phase measurement system using transmission lines

This paper deals with the experimental characterization of an accurate phase measurement system using transmission lines as phase reference. In particular, the used prototype implementing the accurate phase measurement system is also described. The prototype characterization aims of assessing the repeatability of the phase measurement and identifying the systematic effects affecting them. Several transmission lines, priory characterized by means of a Vector Network Analyzer, have been used as phase references. The obtained results demonstrated the standard deviation increases with the sine-wave frequency, while systematic effects are clearly visible at 10 kHz and 100 kHz. The maximum obtained standard deviation at 10 MHz is 0.30 ◦ .

Hongrui Yan, Xinyan Wang, Xiao Liu, Jianbo Liu, Qian Chen, Bin Deng
A new type of rack for the clamp ammeter

In order to improve the calibration ability of the clamp ammeter, realize the simultaneous measurement of single-phase, three-phase and multiple clamp ammeters，and provide technical support for realizing more efficient real-time monitoring of power, this paper analyzed the measurement methods and problems of the clamp ammeters, and studied the measurement principle of the clamp ammeters, then designed a new type of rack for the clamp ammeter. The measurement has been proved that the rack for the clamp ammeter is accurate and efficient.

Marco Coïsson, Javier Diaz De Aguilar Rois, Yolanda Alvarez Sanmamed, Sergio Molto González, Oliver Power, Robert Walsh, Orrie Larmour
Traceability routes for magnetic measurements

Magnetic measurements are vital to support European challenges in areas such as electric vehicles; health; power transformation and harvesting; clean, affordable and secure energy; information and sensor technology. However, only very few European NMIs have the capabilities to perform traceable measurements of all of the most important magnetic quantities. Consequently, the adoption of novel technologies and materials is hindered by the lack of local metrological expertise that research and development activities in academia and industry could exploit. A European project (TRaMM, 21SCP02), in the framework of the Small Collaborative Projects (SCP) call 2021, is transferring the expertise of INRIM (Italy) in the field of magnetic calibration and measurements to CEM (Spain) and NSAI (Ireland), and to interested stakeholders. An update on the training material is given, and new stakeholders are actively sought.

Martina Marzano, Vincenzo D’Elia, Massimo Ortolano, Luca Callegaro
A simple and accurate resistance comparator with a long-scale ratiometric digital multimeter

This paper describes a resistance comparator, based on a long-scale digital multimeter, suitable for primary resistance metrology. The comparator measures the resistance ratio between two fourterminal standards from the readings of the multimeter, when operating in the voltage ratio mode. The quasi-simultaneous measurement of the resistors voltages strongly relaxes the stability requirements of the driving current source with respect to other published comparators, which are based on a shuttling voltage reading. Measurements between resistors of nominal value 12 906 Ω (the quantized Hall resistance) agree with a reference value, given by a dc current comparator bridge, within a few parts in 108 .

Martina Marzano, Cristina Cassiago, Vincenzo D’Elia, Enrico Gasparotto, Luca Callegaro
A calibration procedure for dc resistance ratio bridges

Current comparator bridges are nowadays widespread for the realisation of the resistance unit with the quantum Hall effect and of a midrange resistance scale in most national metrology institutes. Future quantum resistance standards, e.g. those based on novel device materials and tabletop dry cryostats, make the more achievable DC currrent comparator bridges (DCCs) the most viable alternative with respect to the more accurate but more expensive cryogenic current comparator bridges (CCCs). A calibration of the individual DCC ratios of interest by comparison with a reference CCC is a straightforward way to improve the DCC performances. The paper reports a calibration exercise on the ratio 12.9064 kΩ : 1 kΩ, chosen as a benchmark since 12.9064 kΩ is close to the quantized resistance value. A more complete dataset involving also decadal resistance ratios will be presented at the Conference, together with a full evaluation of the calibration uncertainty.

Jakub Svatos, Jan Fischer, Jan Holub
ADC Input Currents Measurement

The contribution introduces the possible issue of internal CMOS Successive Approximation Register microcontroller's Analog-to-Digital Converters input currents. If the microcontroller also contains a multiplexer, it can lead to consequences caused by the sample-and-hold block that is part of a charge redistribution Analog-to-Digital Converter. The article presents its nature, the possibility of its measurement, and a simplified model of such an MCU analog inputs behavior. The simplified model and derived formulas can help the unacquainted user in a data acquisition system with the MCU design when measuring signal sources with non-negligible internal resistance. The introduced parameters, which cannot be found in datasheets, can be essential for users.

Jozef Kromka, Ondrej Kovac, Jan Saliga
Lossless real-time signal encoding for two-channel signals: A case study on ECG

This paper introduces a new encoding algorithm for the lossless, fast, and memory-efficient compression of two-channel signals. The proposed algorithm was evaluated using Electrocardiogram (ECG) signals. The results indicate that it can effectively compress ECG signals with a favorable compression ratio (CR), without relying on complex predictors, dictionaries, detectors, or additional encoding methods. By employing this method, an average CR of 1.98 was achieved, with a minimum CR of 1.54 and a maximum CR of 2.36. Moreover, it is assumed that the algorithm has the potential to enhance the achieved compression in Compressed Sensing (CS) systems.

Page 31 of 939 Results 301 - 310 of 9382