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Autores: Caio César Cunha, Cilis Benevides Aragão, Paulo Régis Carneiro de Araújo, Rhuan Santiago, Andrio Antonio, Henrique Innecco, Jânio Oliveira, Lucas Costa, Samir Sales, Alberto Alexandre

Abstract: Low Power Wide Area Network (LPWAN) represents an excellent option for communicating data in a smart-metering application. This research resulted in a comparative test platform to select, using a study based on methodology and technical and scientific indicators, the best IoT communication platform (network interface card (NIC) + Meter Data Collection (MDC)), which presents the most appropriate technological conditions for smart-meter manufacturers. We are comparing the
technical requirements and indicators of the following IoT platforms: Wireless Smart Ubiquitous Network (Wi-SUN), Hex-NET, and Hybel. Besides that, the KPIs (key performance indicators) comparison platform system is under development to allow the smart-meter manufacturer to choose the best smart-meter communication infrastructure.

Autores: Patricia C de O Vitorio, Leonardo A A de Souza, Regis P Landim, Charles B do Prado

Abstract: The most used methods for determining the ratio of High Voltage Direct Current (HVDC) standard resistive dividers are described in this paper. The binary step-up method was chosen to metrologically characterize a HVDC resistive divider, in order to achieve local traceability to the SI from Josephson Voltage Standards. A Monte Carlo-based simulation was performed to estimate the uncertainty levels of each step from 1.25 kV up to 10 kV, considering that the main components are the uncertainty of the digital multimeter and the voltage source. It was found a variation up to 64-fold in the standard deviation of the voltage output, for a uniform distribution, when the voltage source uncertainty was increased up to 10-fold.

Autor: Marcelo Costa, João Crisóstomo Weyl Albuquerque Costa

Abstract: Optical current sensors can replace traditional current sensor due to their several advantages, as electromagnetic immunity, low dimensions, low cost and others. One of the current main challenges is to develop optical current sensors with good accuracy and stability. This paper presents identification and evaluation of uncertainty contributions to measurement uncertainty evaluation of optical current sensors based on Faraday effect.

Autore: Daniel Slomovitz, Regis P. Landim, Heriguati de Souza, Leonardo Trigo

Abstract: A bilateral comparison between the Instituto Nacional de Metrologia, Qualidade e Tecnología (INMETRO) and the Administración Nacional de Usinas y Trasmisiones Eléctricas (UTE) was performed during 2019 and 2020. The National Laboratory Standards used were two Josephson Voltage Standards at INMETRO (a CJVS and a PJVS), and a bank of multiple Zeners at UTE, both at 10 V level. The traveling standards were two commercial Zener based sources. The INMETRO was the pilot laboratory and the comparison error was (-1.79 ± 2.55) parts in 107 , k=2.

Autores: Mauro Vieira de Lima, Fernando A. Rodrigues

Abstract: One of the main goals of time and frequency transfer is clock comparison between stations separated by large distances. The comparison allows the monitoring of the clock’s performance, including, for instance its long-term stability in terms of its time scale or frequency. In metrology, the interest in the precision and accuracy of measurements stands out. In applications that are based on time or frequency, synchronism to a universal time scale is a requirement to maintain traceability, security and compatibility with other systems. Therefore, the basis for creating and disseminating a universal time scale is a reliable comparison between the clocks in different stations. TWSTFT is one of the most accurate methods for comparing and synchronizing time scales between remote stations connected by a geostationary satellite, whose clocks are references as time and frequency standards. The TWSTFT system can provide a time uncertainty smaller than one nanosecond and provide time and frequency transfer without the main vulnerabilities of GNSS. This paper presents the TWSTFT technique and the feasibility of using TWSTFT to provide traceability in the Brazilian context.

Autores: Arlindo dos Santos Rebelo Júnior

Abstract: In high-accuracy Mass Metrology, the control of weighing and environmental conditions has an important value, these factors has a huge influence on the results, as well as on, the performance of the equipment used. In this work, the performance of an ultra-micro mass comparator was evaluated before and after being submitted to a period of instability on the laboratory environmental conditions. The standard deviation and the drift commanded by the instrument were compared before and after the event occurred. According to the results obtained, it was observed that after the instability of the environmental conditions, the standard deviation was out of the required limits by the laboratory’s quality system. Additionally, there is a significant increase in the instrument’s drift. Through the results it ́s possible to conclude that the instrument affected by the variations in a way that it no longer reaches the requirements demanded by the laboratory’s Quality System.

Autores: Fabio Andre Ludolf Cacais, Victor Loayza, Anderson Beatrici, Davi Quintão, Arlindo Rebelo

Abstract: This work shows the results obtained by Inmetro’s mass lab implementation of a simple Kibble balance approach for demonstration of its mass measurement principle based on the Planck’s constant. It is based on some modifications of Mimimal Watt Balance work reducing the required electrical measurements by using two loudspeakers mechanically coupled so that one of them acts as a linear actuator in order to perform BL measurements in the moving phase. The mean BL value obtained in weighing phase was 2.66 N/A and in moving phase 2.67 N/A. The maximum error of mass values measured for standard weights in the range from 5 g to 50 g was lower than 5%.

Autores: Marcella Rocha, Davi Quintã

Abstract: Abstract. Mass is one of the basic quantities of the International System of Units (SI), its measurement is essential for several fields. The Mass Laboratory (Lamas) of the National Institute of Metrology, Quality and Technology (Inmetro), is responsible in Brazil for providing traceability of mass, through the National Kilogram Prototype (K66) which has direct traceability to the International Kilogram Prototype (IPK) which is related to Planck’s constant after redefinition of the kilogram. Mass traceability is given through documented unbroken chain of standard weights and balances calibrations. Calibration of balances is one of Lamas’ activities that provides traceability to other areas such as chemical metrology, biotechnology and other mechanical quantities. Analytical balances have an adjustment procedure that ideally restores the factory settings, but over time and continued use, the analytical balances may be not adjusted and significantly influence the instruments indications. This work aims to determine how long an analytical balance remains adjusted through the results of calibrations over time. From the calibrations, the normalized errors have been calculated and it has been concluded that the adjustment modifies the balance errors of indication and that the balance is out of adjustment in less than a week.

Autor: Anderson Beatrici

Abstract: The calibration or checking of mass standards collections is an important activity in mass Metrology laboratories to provide traceability to the kg. To improve the laboratory measurement capabilities it´s necessary to know and assess all influences on the results accuracy. This uncertainty budget depends on many factors, the measurement standard deviation (SD) being one of the most important. The equipment studied was designed with the possibility of using two weighing chambers to avoid, or at least reduce, the effects of environmental changes. In high-accuracy measurements or in places without excellent environmental control it´s necessary to use these two weighing chambers to achieve the desired results. In this study will be present some tests of the effect of weighing chambers on standard deviations and in mass measurements results. The results indicate that using at least one weighing chamber is possible to achieved acceptable results to E1 calibrations (to mass nominal values greater than 10 g), but the use of double weighing chambers improves the stability of the system at least six times than using only one chamber.

Autores: Marcio Antonio Sens, Carlos Frederico Trotta Matt

Resumo: An experimental, non-destructive and non-invasive technique for the quick and accurate detection of the internal conditions of electromagnetic reactors for HVDC systems has been used successfully. This technique involves the application of mechanical vibrations, in scanning to find resonance frequencies and the maintenance of vibrations in these frequencies with discrete evaluation of the electrical impedance of the reactor. With the vibrations, it was identified that the unit contained moving and non-static parts as expected in healthy units. And yet, those moving parts could be moved permanently when vibrations in the resonant frequencies were applied, in safe amplitudes so as not to cause other damages.