Kevwords -Microwave measurements, refection and transmission coeflcients, free-space method, cement-based materials, mortar, concrete, hydration, water-to-cement ratio, curing, dielectrc permittivity.
In order to update and improve INTI’s AC-DC current transfer capabilities, we developed three different types of 5 and 10 A shunts for the AC-DC current transfer measurements included in a new AC-DC Transfer Step-Up scheme. The... more
The reaction rate of the copper-catalyzed oxidation of iodide by oxygen in an aqueous acidic medium is first order in copper and oxygen concentrations, Michaelis-Menten in pH and a complex, asymmetrical bell shaped function in iodide... more
This paper presents a simplified model for the evaluation of the measurement uncertainty of pressure balance effective area calibrated by method of comparison which is being applied at Laboratory for Process Measurements (LPM). The... more
This paper presents a hysteresis model for electromagnetic sensors and actuators, which are composed of ferromagnetic materials. The model is based on the Preisach operator, which is capable to fully describe major as well as minor... more
The design of a new generation of planar multijunction thermal converters (PMJTCs) on quartz membranes and on quartz crystal chips improves the frequency response of the PMJTC in the frequency range from 100 kHz to 100 MHz and allows a... more
The new generation of PMJTCs on quartz crystal chips and on quartz membranes developed at the Physikalisch-Technische Bundesanstalt (PTB) results in new calculable ac-dc current transfer standards for a current of 10 mA in the frequency... more
Centro Español de Metrología (CEM) has developed a new ac-dc current standard to improve our measurement capabilities and extend the measurement range to 100 A and 100 kHz. The new standard is based on a step-up procedure using the... more
Required metrological tools, such as higher order reference measurements procedures, pure substance and matrix certified reference materials, are established for small well defined molecules. Difficulties still remain in the provision of... more
Required metrological tools, such as higher order reference measurements procedures, pure substance and matrix certified reference materials, are established for small well defined molecules. Difficulties still remain in the provision of... more
Required metrological tools, such as higher order reference measurements procedures, pure substance and matrix certified reference materials, are established for small well defined molecules. Difficulties still remain in the provision of... more
Under the auspices of the Protein Analysis Working Group (PAWG) of the Comité Consultatif pour la Quantité de Matière (CCQM) a pilot study, CCQM-P55.2, was coordinated by the Bureau International des Poids et Mesures (BIPM) and the... more
A cage-type, current-shunt construction design was adopted in this work as prospectively having a wide bandwidth. A lumped equivalent circuit model for current shunts assembled according to this design is described here. The ac-dc... more
This paper describes a simple model for planar multi-junction thermal converters based on physical dimensions and properties of the converter chip and all wire bonds. The model was used to explain extremely low (< 700 µV/V) AC-DC... more
New ac-dc current transfer standards are built for the current range from 0.3 mA to 20 A and the frequency range from 10 Hz to 100 kHz. A three-dimensional PTB-multijunction thermal converter (MJTC) with a heater resistance of 27 is the... more
Planar multijunction thermal converters (PMJTC) on quartz crystal chips and membranes have been fabricated. Compared to previous single-junction thermal converters, these devices exhibit calculable and smaller ac-dc voltage transfer... more
Coaxial, thermal voltage converters were handcarried among NIST, NPL, PTB, and VSL for intercomparison of ac-dc difference from 100 kHz to 1 MHz. This paper briefly describes the highly varied methods and underlying principles on which... more
Ever since the first publication of intracavity optogalvanic spectroscopy (ICOGS) in 2008, this novel technique for measuring the 14 C/ 12 C ratio in carbon dioxide has rendered considerable attention. As a result, there are currently at... more
The reaction rate of the copper-catalyzed oxidation of iodide by oxygen in an aqueous acidic medium is first order in copper and oxygen concentrations, Michaelis-Menten in pH and a complex, asymmetrical bell shaped function in iodide... more
Required metrological tools, such as higher order reference measurements procedures, pure substance and matrix certified reference materials, are established for small well defined molecules. Difficulties still remain in the provision of... more
In this paper, we present a framework to analyze the propagation of measurement errors through the body composition equations. This is done through the equations for body composition assessment (BCA), for single/multifrequency (SF, MF)... more
A new type of coaxial shunt for high frequency ac-dc current transfer standards has been designed. The structure of the shunts with nominal current from 100 mA to 5 A are made of a disk with two coaxial conductive layers in one side. SMD... more
We report on the development of thin-film multijunction thermal converters for the measurement of ac current. The materials and designs chosen for these devices have been optimized to provide high accuracy over a wide range of input... more
We report on the development of thin-film multijunction thermal converters for the measurement of ac currents up to 10 A without relying on parallel current shunts. The materials and designs chosen for these devices have been optimized to... more
In this study, the Coleman-hysteresis model is utilised in the piezoelectric actuator (PZTA) dynamic model and a non-linear robust control strategy is then developed to actively control the displacement of the PZTA effective tip. The... more
Under the auspices of the Protein Analysis Working Group (PAWG) of the Comité Consultatif pour la Quantité de Matière (CCQM) a pilot study, CCQM-P55.2, was coordinated by the Bureau International des Poids et Mesures (BIPM) and the... more
This paper proposes a virtual tool for load flow analysis in energy distribution systems of micro-grids. The solution is based on a low-cost measurement architecture, which entails low-voltage power measurements in each secondary... more
This paper describes a laboratory method for the determination of the pressure balance piston fall rate using a simple camera-based optical system with internally developed software. Measurements were carried out on three standard... more
This paper describes a laboratory method for the determination of the pressure balance piston fall rate using a simple camera-based optical system with internally developed software. Measurements were carried out on three standard... more
Both SI units, the candela and the kelvin were originally derived from standard blackbody sources. Recently, instead of source-based calibrations, they both have been realized with optical detector standards [1, 2]. Recent decrease of the... more
This paper presents a measurement comparison of WM-864 (WR-03) precision waveguide lines for use as reference standards in the Thru-Reflect-Line (TRL) calibration method for VNAs at millimeter and sub-millimeter wave frequencies (in this... more
This paper proposes a virtual tool for load flow analysis in energy distribution systems of micro-grids. The solution is based on a low-cost measurement architecture, which entails low-voltage power measurements in each secondary... more
This paper presents a simplified model for the evaluation of the measurement uncertainty of pressure balance effective area calibrated by method of comparison which is being applied at Laboratory for Process Measurements (LPM). The... more
Planar multijunction thermal converters (PMJTC) on quartz crystal chips and membranes have been fabricated. Compared to previous single-junction thermal converters, these devices exhibit calculable and smaller ac-dc voltage transfer... more
In this paper, an explanation for the ac-dc voltage transfer differences at frequencies greater than 100 kHz of the standard thin-film or planar multijunction thermal converter (PMJTC) developed at the Physikalisch-Technische... more
This paper describes in details a new design of a fully automated multiple output micropotentiometer (pot). A prototype has been built at the National Institute for Standards (NIS), Egypt to establish this highly improved AC voltage... more
In the available literature there are various approaches to solving and explaining whiplash movement of head and neck. Regardless of the fact that the mentioned movement has been the subject of numerous studies and discussions, it is... more
The low-frequency ac-dc voltage transfer differences of thermal converters for higher voltages with planar multijunction thermal converters (PMJTCs) and series resistors have been determined by using only the assumption of a linear change... more
New planar multijunction thermal converters (PMJTCs) with low-power coefficient and high dynamic range using CuNi44/BiSbTe thermocouples have been manufactured. In series connection with carefully evaluated range resistors for voltages up... more
With bismuth-antimony thermocouples, the responsivity of the thin-film multijunction thermal converter has been improved to 16 VW-' in air and 120 VW-' in vacuum. With these converters the ac-dc voltage transfer has been extended into the... more
The new generation of PMJTCs on quartz crystal chips and on quartz membranes developed at the Physikalisch-Technische Bundesanstalt (PTB) results in new calculable ac-dc current transfer standards for a current of 10 mA in the frequency... more
The thermoelectric transfer difference of Thermal Converters (TCs) can be evaluated in both current mode and voltage mode, using a fast-reversed dc (FRDC) source. Some types of TCs show differences in the thermoelectric transfer... more
In the Electrotechnical Laboratory (ETL) the accuracy of the ac-dc voltage transfer difference has been improved for the voltage range from 1-20 V in the frequency range from 10 Hz to 100 kHz. At the same time, the ac-dc transfer... more
The paper presents the National Research Council (NRC) activities to establish and maintain acdc transfer difference standards of voltage and current at the lowest achievable uncertainty levels. It describes the AC Josephson Voltage... more
NRC offers calibration of ac shunts from milliamperes up to 100 A, in the 10 Hz to 100 kHz frequency band with expanded uncertainties between 10 µA/A for currents in the milliampere range to 50 µA/A at 100 A and 100 kHz. The paper... more
This paper summaries a bilateral comparison of measurement of the diameters of two precision 1.85 mm coaxial air lines. These dimensional measurements were made independently by two national metrology institutes: NMIJ and NPL. The... more