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This paper describes a system for generating and measuring extremely accurate phase angles that combines the digital synchronous signal generation with the synchronous subsampling technique, aided by digital phase regulation. The system can be set up with commercially available instrumentation. Experimental evidences suggest that the phase between two generated sine signals can be resolved to a few microradians up to the megahertz range.

This paper describes three impedance bridges in operation at INMETRO: the two- and four-terminal-pair coaxial bridges and a digital quadrature bridge, including several comparisons among them in the nanofarad capacitance range. These comparisons have the objective to verify the performance and reliability of the coaxial bridges between themselves and to infer on the capabilities of a digital one, recently put in operation. The results obtained indicate that the more accurate coaxial systems are compatible with one another in the $10^{-7}$ level. The digital bridge is in agreement with the coaxial ones within a few parts in $10^{6}$ or even less in some cases.

This paper describes a five-terminal (four terminal with shield) digital impedance bridge aided by digital adaptive phase regulation. It allows the comparison of ac resistances and capacitances with outstanding accuracy and with measurement uncertainties bearing only some $10^{\mathrm { {-6}}} \Omega /\Omega $ , as corroborated by extensive experimental investigations.

Power system transient analysis relies on the deployment of models with ever-increasing accuracy that represents the system's frequency-dependent components with respect to the phenomena being scrutinized. A key issue in this context is the construction of a model yielding passive properties for each system component. Such properties are commonly compromised by corrupting noise in measurements that serve as input to the computation of blackbox models. In addition, model passivity could be further compromised during parameter estimation. This paper undertakes the task of developing a proposal to build an optimization methodology based on linear matrix inequalities (LMI-based) which is intended for obtaining an optimal, passive, blackbox model for a $n$ -terminal power transformer. The resulting model can be further realized as a circuit representation in order to simulate the transformer dynamics in an Eletromagnetic Transient program (EMT type). The results derived from two operating power transformers are later provided to confirm how effective the procedure herein proposed is.

This paper describes the design for a thermal converter (TC) with frequency output under development at INMETRO. The TC uses commercially available discrete components, eliminating the need for large investments in special environments (clean rooms) for its construction. Today's available surface-mount resistors for high frequency applications display nearly pure resistive behavior up to the GHz region, enabling the operation of the TC in a wide frequency range. A thermistor is used as temperature sensor, connected to an oscillator in order to provide a frequency output proportional to the input power.

This paper describes capacitance comparisons among three impedance bridges in operation at Inmetro in the nF range: the two- and four-terminal-pair coaxial bridges and a digital quadrature bridge. This comparison has the objective to verify the performance and reliability of the coaxial bridges between themselves and to infer on the capabilities of a digital one, recently put in operation. The results obtained indicate that the more accurate coaxial systems are compatible to one another in the 10−7 level. The digital bridge is in agreement with the coaxial ones within parts in 106.

This paper describes the development of a primary single-phase sampling ac power standard, which uses a programmable Josephson voltage standard (PJVS) in its core. Magnetic transducers are used to scale down to low levels the ac signals to be compared with the PJVS by digital sampling. Independent digital adaptive regulators in form of algorithms in a control software guarantee stable and accurate phase alignment of the ac signals up to some nano radian.

This paper describes a system for generating and measuring extremely accurate phase angles that combines the digital synchronous signal generation with the synchronous subsampling technique, aided by digital phase regulators. The system can be set up with commercially available instrumentation with a minimum of hardware development. Experimental evidences suggest that the phase between two generated sine signals can be resolved to a few μrad up to the MHz range.

This paper describes the development of an automated ac current comparator based resistance measurement system that uses precise and accurate phase synchronization of frequency locked ac signals aided by adaptive digital regulators. The aimed frequency range lies between 1 Hz to 20 Hz.

In the central zone of the Emeishan Large Igneous Province (ELIP), southwestern China, the Permian Emeishan continental flood basalts (ECFB) can be divided into high- and low-Ti basalts and alkaline basalts. At the southern margins of the central ELIP, the low- and high-Ti basalts comprise the lower and upper parts of the ECFB sequences, respectively; the alkaline basalts occur in the lower part of the ECFB sequence in a few locations. The high-Ti basalts are high in Pd (4-16 ppb) and Pt (7–18 ppb), but have large variations in Ir (0.04–0.88 ppb). The alkaline basalts have low TiO2 contents (1.8–2.15 wt.%) and are depleted in PGE ( 30,000) and very low Pt/Y ratios (230 to as low as 6) strongly suggest that the PGE-depletion in the low-Ti basalts and alkaline basalts is related to sulfide removal. The positive relationship between Pt and Pd depletion and increases in Zr/Nb and Th/Nb ratios indicate that crustal contamination played a role in driving the low-Ti basaltic magmas to S-saturation. In contrast, for the PGE-undepleted high- and low-Ti basalts, Pd decreases slightly with decreasing MgO and Ir, and Pd/Cr ratios increase with decreasing Pt/Y, indicating that fractionation occurred under S-undersaturated conditions. Some PGE-undepleted low-Ti basalts have very high Pd/Pt ratios (up to 6, much higher than that of the primitive mantle ~ 0.6) and extremely low Ir concentrations (

Metals have been central to the development of human civilisation from the Bronze Age to modern times, although in the past, metal mining and smelting have been the cause of serious environmental pollution with the potential to harm human health. Despite problems from artisanal mining in some developing countries, modern mining to Western standards now uses the best available mining technology combined with environmental monitoring, mitigation and remediation measures to limit emissions to the environment. This paper develops risk screening and prioritisation methods previously used for contaminated land on military and civilian sites and engineering systems for the analysis and prioritisation of chemical risks from modern metal mining operations. It uses hierarchical holographic modelling and multi-criteria decision making to analyse and prioritise the risks from potentially hazardous inorganic chemical substances released by mining operations. A case study of an active platinum group metals mine in South Africa is used to demonstrate the potential of the method. This risk-based methodology for identifying, filtering and ranking mining-related environmental and human health risks can be used to identify exposure media of greatest concern to inform risk management. It also provides a practical decision-making tool for mine acquisition and helps to communicate risk to all members of mining operation teams.

The present PTB primary standard allows power measurements with a measurement uncertainty of about 2.5 μW / VA (k = 2). It operates at voltages up to 240 V and currents up to 10 A in the frequency range from 16 Hz up to some kHz. This paper gives a short overview of the working principle of the standard and recent improvements.

The Jinchuan deposit, NW China, is one of the world’s most important Ni-Cu-(PGE) sulfide deposits related to a magma conduit system and is hosted in an ultramafic intrusion. The intrusion is composed of lherzolite and dunite with the two largest sulfide ore bodies (named as ore body 1 and 2) in its middle portion. The sulfide ores may be disseminated, net-textured, or massive. The disseminated and net-textured sulfide ores are characterized by variable but generally low PGE concentrations: 10–3200 ppb Pt, 240–9800 ppb Pd, 17–800 ppb Ir, 25–1500 ppb Ru, and 15–400 ppb Rh in 100% sulfides. The massive sulfide ores are extremely low in Pt ( 4 to 4.5 × 10 5 . The low PGE contents suggest that the sulfide ores formed from the silicate magmas that had already experienced prior-sulfide separation. Our calculations indicate that if the first stage basaltic magmas had contained 6.3 ppb Pt, 6.2 ppb Pd, and 0.1 ppb Ir, 0.008% sulfide removal would result in PGE-depletion in the residual magma with 0.57 ppb Pt, 0.25 ppb Pd, and 0.009 ppb Ir. The Jinchuan sulfides were formed by a second stage of sulfide segregation from a PGE-depleted magma under silicate/sulfide liquid ratios (R-factor) ranging from 10 3 to 10 4 in a deep-seated staging chamber. The massive sulfide ores and some of the net-textured sulfide ores exhibit strong negative Pt-anomalies that cannot be explained by sulfide segregation under variable R-factors. Instead, the sulfide melts that formed the massive ores were segregated from magmas experienced prior fractionation of Pt–Fe alloy. Alternatively, the Pt may have been selectively leached by hydrothermal fluids during remobilization of the sulfide melts that produced the massive sulfides, which occur in cross-cutting veins. We propose that the Jinchuan intrusion and ore bodies were formed by injections of sulfide-free and sulfide-bearing olivine mushes from a deep-seated staging chamber.

An easy-to-use and low-cost quasi-synchronous multichannel digital sampler controller to aid routine laboratory ac measurements by digital sampling is described. Using a single digital sampling voltmeter, accurate measurements of ac quantities can easily be done with uncertainties of a few microvolts per volt. Measurement results and consistent uncertainty calculations are described

A recent upgrade of the primary standard for electric alternating power at the Physikalisch-Technische Bundesanstalt improved the measurements, indicating that standard uncertainties of the order of 1 muW/VA are attainable. Investigations done to ensure such low uncertainty figures are presented, and the evaluation of measurement uncertainties is discussed in detail

This paper describes the accurate methods for the determination of power quality parameters. The methods and procedures described apply to the measurement of harmonics, flicker, fluctuating harmonics, and interharmonics and allow uncertainties of some parts in 106 to be attained

The present commercially available ac amplifiers for testing and calibration purposes generally use electronic devices operating at high power levels. These amplifiers are rather prone to instabilities and usually produce a noticeable amount of heat, which must be vented to the ambient. The design of a simple and inexpensive precision ac voltage amplifier is presented, in which all internal electronic devices operate at low power and consequently produce less heat. The measured gain stabilities (amplitude and phase) of the amplifier were around /spl plusmn/1 /spl mu/V/V and /spl plusmn/1 /spl mu/rad, respectively, over 30 min.

Measurements of AC quantities with thermal converters are very time consuming. Efficient proposals based on simple models and on the concept of state variables to speed-up AC-DC transfer measurements without loss of accuracy are made.

Analyses of thermal converters using field-effect transistors as heater elements are presented. Numerical simulations and experimental evaluations show that field-effect transistor thermal converters (FET-TCs) display outstanding metrological capabilities. These devices allow a direct multiplication of two alternating current (ac) quantities by a direct thermal conversion to be made without intermediate steps. It is shown that their high frequency bandwidth and fast thermal response time of the order of some seconds permit the determination of the true root-mean-square (rms) value of ac quantities with uncertainties of the order of a few μV/V.

The simultaneous synchronous generation and sampling technique allows alternating current (AC) quantities (root mean square (RMS) values of voltage, voltage ratios, and power) to be determined with uncertainties of the order of a few parts in 10/sup 6/. Mathematical models for estimating measurement uncertainties and experimental comparisons of such a system against existing primary standards at the PTB were carried out.

The Sakatti Cu-Ni-PGE sulfide deposit was discovered by Anglo American in northern Finland in 2009. It consists of both disseminated and massive sulfides, hosted by a large olivine cumulate body, surrounded by volcanic rocks that make up the footwall and part of the hanging wall. A polymict breccia constitutes the majority of the hanging wall. Two smaller satellite olivine cumulate bodies also host mineralization. The sulfide mineralization is generally Cu-dominated, especially in the shallower part of the deposit, with a transition to more Ni-rich and Ni-dominated mineralization in its deeper part. Disseminated mineralization is only found within the olivine cumulate bodies, whereas massive sulfides extend up to 150 m into the footwall, where they rapidly evolve toward very low Ni/Cu ratios.

The paper describes the quantum vector digital voltmeter developed at INMETRO, which is based on a programmable Josephson voltage synthesizer. The system employs digital regulation for phase-alignment and frequency synchronization of signals, is fully automated and allows calibration of ac sources and analog-to-digital converters with uncertainties bearing some parts of 10-07 up to frequencies of around 500 Hz.

This paper pinpoints some design aspects on RC-oscillators for the synthesis of pure sine waveforms aimed at characterizing nonlinear distortion of high-resolution analog-to-digital converters. Preliminary results for a specific RC-oscillator indicate 2nd harmonic distortion 110 dB below carrier and much lower than this for higher order harmonics. Some ADC characterization results are shown.

The soap film analogy is a tool for analysing potential flow in complex geometries. It has been used around 1960 in Dresden to investigate the flow in high-pressure turbine cascades. The present paper briefly reviews the technique and reports on the comparison between historical results, achieved with the soap film analogy, and numerical simulations. It illustrates the capabilities of the method and the historical progress made since then. (© 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)

This paper describes the setup of the modernized instrument transformer burden measurement system of the Physikalisch-Technische Bundesanstalt. Its measuring ranges cover burden ranges up to several 100 VA of conventional current transformers (CT) and voltage transformers (VT) according to the relevant IEC and ANSI standards.

The measurement of the severity of electric light flicker is achieved using a complex model of the human response embodied in a flickermeter. The complex nature of the model leads to variations in flicker readings with voltage input that can be hard to predict. Uncertainty evaluation is therefore difficult to achieve by conventional methods and a Monte Carlo approach is required. This paper describes the implementation of such an approach to evaluate the uncertainty for flicker measurements based on a model of the measurement process.

This paper describes the new PTB three-phase alternating (ac) power sampling standard. Based on two cascaded direct-digital-synthesizers, it allows calibrations with high frequency-resolution. The system is intended to reduce measurement uncertainties of three-phase power meter calibrations to less than 10 muW/VA and to alleviate staff's daily burden of calibration routine.

This paper describes advances in the hardware design of a system for characterizing and investigating high-resolution sigma-delta analog-to-digital converters. This work is being done in the frame of a Ph.D. study program in electrical engineering at the TU-BS, focusing the characterization and modeling of such converters with the help of sinusoidal and the PTB Josephson waveform synthesizers. An effective resolution of 18-19 bits at a sampling rate of 64 kHz has been attained.

This paper presents the realization of a compact two- channel microcontroller-based digital synthesizer (CMDS) for generating accurate alternating (ac) voltage signals aiming at improving ac measurement techniques at AIST. Device description and the measurement techniques employed for evaluating it are described. First evaluations indicate that the CMDS may be used in high-grade ac Metrology.

SEVENTH BRAZILIAN CONGRESS ON METROLOGY (METROLOGIA 2013) Metrology and Quality for a Sustainable Development From November 24th to 27th 2013 was issued the Seventh Brazilian Congress on Metrology (Metrologia 2013), which is a biannual conference organized and sponsored by the Brazilian Society of Metrology (SBM) and the Brazilian National Institute of Metrology, Quality and Technology (Inmetro). This edition was held in the charming and historical city of Ouro Preto, MG, Brazil, and aimed to join people and institutions devoted to the dissemination of the metrology and conformity assessment. The Metrologia 2013 Conference consisted of Keynote Speeches (7) and regular papers (204). Among the regular papers, the 47 most outstanding ones, comprising a high quality content on Metrology and Conformity Assessment, were selected to be published in this issue of the Journal of Physics: Conference Series. The topics of the conference covered all important areas of Metrology, which were agglutinated in the following sessions in the present issue: Physical Metrology (Acoustics, Vibration and Ultrasound; Electricity and Magnetism; Mechanics; Optics); Metrology on Ionizing Radiations; Time and Frequency; Chemistry Metrology; Materials Metrology; Biotechnology; Uncertainty, Statistics and Mathematics; Legal Metrology; Conformity Assessment. It is our great pleasure to present this volume of IOP Journal of Physics: Conference Series (JPCS) to the scientific community to promote further research in Metrology and related areas. We believe that this volume will be both an excellent source of scientific material in the fast evolving fields that were covered by Metrologia 2013. President of the congress Americo Bernardes Federal University of Ouro Preto atb@iceb.ufop.br Editor-in-chief Rodrigo Costa-Felix Brazilian National Institute of Metrology, Quality and Technology rpfelix@inmetro.gov.br Editors Jose Carlos Valente de Oliveira (Editor on Mechanical Metrology) Brazilian National Institute of Metrology, Quality and Technology jcoliveira@inmetro.gov.br Jose Mauro Granjeiro (Editor on Biotechnology) Brazilian National Institute of Metrology, Quality and Technology jmgranjeiro@inmetro.gov.br Ruth Epsztejn (Editor on Conformity Assessment) Brazilian National Institute of Metrology, Quality and Technology repsztejn@inmetro.gov.br Waldemar Ihlenfeld (Editor on Electrical Metrology) Brazilian National Institute of Metrology, Quality and Technology wgihlenfeld-pronametro@inmetro.gov.br Valnei Smarcaro da Cunha (Editor on Chemistry Metrology) Brazilian National Institute of Metrology, Quality and Technology vscunha@inmetro.gov.br Technical and Scientific Committee for Metrologia 2013 Ado Jorio (UFMG) Carlos Achete (UFRJ, Inmetro) Flavio Vasconcelos (UFMG) Giorgio Moscati (USP) Hans Peter Grieneisen (Inmetro) Humberto Brandi (Inmetro) Jose Carlos Valente de Oliveira (Inmetro) Jose Guilherme Pereira Peixoto (IRD) Jose Mauro Granjeiro (Inmetro) Luiz Claudio Moreira Paschoal (Petrobras) Luis Fernado Rust (Inmetro) Luiz Silva Mello (PUC RJ) Marcos Nogueira Eberlin (Unicamp) Oleksii Kuznetsov (Inmetro) Regis Landim (Inmetro) Ricardo Carvalho (ON) Rodrigo Costa-Felix (Inmetro) Romeu Jose Daroda (Inmetro) Ruth Epsztejn (Inmetro) Valnei Smarcaro da Cunha (Inmetro) Valter Aibe (Inmetro) Waldemar Guilherme Kurten Ihlenfeld (PTB) Wanderley de Souza (UFRJ, Inmetro)

A progress in three-terminal thermoconverter (TTTC) sensor and corresponding power measurement technique is described. Thermal and electrical models of sensor microsystems were developed to optimise construction and minimise residual parameters affecting power conversion accuracy.

Field Effect Transistor Thermal Converters (FET-TCs) use FETs working as dynamically controlled impedances, enabling an exact control of the dissipated power proportional to the product of the FET's drain voltage and source current. The temperature increase caused is directly proportional to the time-averaged internally dissipated power. A FET-TC based on MOSFETs was analysed from the thermal and electrical point of view and constructed to measure rms values of electrical ac quantities including power with uncertainties in the ppm level.