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S. Winter, T. Fey, I. Kröger, D. Friedrich, K. Ladner, B. Ortel, S. Pendsa, D. Schlüssel
DESIGN AND REALIZATION OF A NEXT GENERATION HIGH ACCURACY PRIMARY CALIBRATION FACILITY FOR SOLAR CELLS AT PTB

A completely newly designed multifunctional flexible facility for the primary calibration of reference solar cells and the spectral characterization of all solar cell types has been developed and built at PTB. The new facility is based on the successfully applied Differential Spectral Responsivity (DSR) method that allows the determination of the absolute spectral responsivity and nonlinearity of solar cells with the lowest uncertainties. By using a tunable laser system, the new setup avoids the main problem of monochromator-based systems: the low optical power level of the monochromatic beam. Thus it enables a significant reduction of the uncertainty for the short circuit current under standard test conditions ISTC of large solar cells.

J. Dubard, J.-R. Filtz, V. Cassagne, P. Legrain
SOLAR METROLOGY: PHOTOVOLTAIC MODULE PERFORMANCE MEASUREMENTS

The performance of a photovoltaic module is mainly defined by the maximum power Pmax, which is measured under standard conditions (1000 W/m², AM 1.5, 25°C) using a sunlight (natural or simulated) and a calibrated reference device. This reference photovoltaic device, placed in the same lighting conditions than the module under test, allows the measurement of the sunlight levels through the monitoring of the maximum power of these devices. As a key metric for photovoltaics economy, the measurement of Pmax must be a subject of a strong attention. This paper describes the metrology applied and the typical levels of uncertainties achievable by National Laboratories as well as in the Industry.

T. Kurczveil, P. Diekhake, J. Liu, E. Schnieder
ENERGY MEASUREMENT FOR CONSUMER LOADS IN BUILDINGS USING FIELD BUS SYSTEM FOR HOME AUTOMATION

Energy is one of the most important fundamentals of modern societies. Due to limited resources, the responsible use is becoming increasingly urgent. Particularly in buildings the energy consumption can be reduced significantly by applying intelligent solutions. One basis for these solutions, such as load management for optimized energy distribution, is the energy metering of components in electric systems. In this abstract, a field bus system is presented that, due to its local distribution, is suitable for energy consumption measurement of its individual components. After presenting the bus system, its concept, and a summary of the mathematic algorithm, an example application will be shown to exemplify the functionality.

Moo-Young Seok, Dong-Hyun Lee, Jung-A Lee, Yong-Jae Kim, Yun-Hee Lee, Un Bong Baek, Seung Hoon Nahm, Jae-il Jang
INFLUENCES OF HYDROGEN ON THE MECHANICAL BEHAVIOR OF WELD HEAT-AFFECTED ZONE IN API STEEL PIPELINE

To prepare the up-coming era of so-called ‘hydrogen economy,’ many researches on the related infrastructures are actively conducted around the world. One of the important issues on the topic is hydrogen transmission. Recently, the use of existing natural gas pipeline is often considered as an cost-effective way of hydrogen transmission. However, while much researches have been performed on the possible hydrogen effects on the mechanical performance of pipeline steels, few study has been reported for the influence of hydrogen on the mechanical behavior of their weld heat-affected zone (HAZ), that is well known to be the weakest in the pipeline. In the present study, various HAZs are simulated, and the hydrogen effects on their mechanical behavior were systematically investigated through indentation, tensile tests, and impact tests.

Klaus-Dieter Sommer, Stefan Sarge, Petra Spitzer, Ruediger Kessel
ENERGY MEASUREMENT AND STANDARDS – AN OVERVIEW

The establishment of a sustainable energy supply as well as of achieving efficient energy consumption furnish one of the grand challenges and technological mega trends of today and the decades to come. Energy research and development and even field measurements for novel and renewable energies, for transmission and distribution as well as for large-scale energy storage are significantly lacking in appropriate measurement technologies, measurement standards and traceability schemes. An overview is given on the most relevant open questions and challenges to metrology. The known approaches chosen are mentioned. Special attention is drawn to the current metrological research for energy in Europe.

A. Yun-Hee Lee, B. Yongil Kim, C. Jongseo Park, D. Unbong Baek, E. Kwon Sang Ryu
DEVELOPMENT OF A REFERENCE MATERIAL FOR HYDROGEN CONTENTS MEASUREMENT

By heating a metal sample exposed to hydrogen environment until its melting point, whole hydrogen can be released and its content is quantitatively measured with a thermal conductivity detector (TCD). Reference materials with already-known hydrogen contents are needed to calibrate the detector. In this study, we proposed a new concept for making the reference material; the targeted hydrogen content can be obtained by controlling mixing amount of a hydride with its balancing weight. The hydrogen contents can be roughly calculated by considering the chemical stoichiometry of the hydride. A linear proportional relationship was identified between the calculated hydrogen contents and the empirically measured values from the detector. However, both hydrogen contents did not coincide with each other numerically. This phenomenon was discussed from several factors such as partial hydrogenation and air-bone contaminants in the hydride, inconsistent calibration procedure, impurity involved in the measurement, etc.

Seok Cheol Lee, Hoon Sik Jang, Ho Jong Kim, Un Bong Baek, Chang Soo Kim, Seung Hoon Nahm
DEVELOPMENT OF HYDROGEN LEAKAGE MEASUREMENT DEVICES BASED ON WIRELESS SENSOR NETWORKS

This paper describes the wireless sensor network based measurement devices for hydrogen leakage detection and monitoring. The hydrogen is gaining much attention as a possible future substitute for fossil fuel in the transport sector but hydrogen energy should be used with caution and always involves the safety management devices. We suggest the measurement devices for hydrogen leakage based on the wireless sensor networks(WSNs). Our proposed device model supports the measurement of hydrogen leakage quantities and mobility by wireless communications.

S. Seitz, P. Spitzer, F. Durbiano, H. Jensen
ELECTROLYTIC CONDUCTIVITY AS A QUALITY INDICATOR FOR BIOETHANOL

This work introduces the European Metrology Research Project on the SI traceability of electrolytic conductivity measurements in bioethanol. As a first step to this aim secondary conductivity measurements have been performed to characterise reproducibility, stability, measurement uncertainty and the significance of the measurement results. The standard measurement uncertainty is in the order of 0.3 %. Two samples from different sources show significantly different conductivity values. The results indicate that conductivity is an appropriate quality indicator for bioethanol.

T. Hager, A. Bentaleb, E.-A. Wehrmann
SIMULATION SYSTEM WITH CALORIFIC VALUE TRACKING FOR GAS DISTRIBUTION GRIDS WITH AN INCOMPLETE MEASUREMENT INFRASTRUCTURE

State of the art in the use of gas quality tracking systems for billing purposes are systems for transmission grids, where all inlets and rather all offtakes are measured. Such a complete measurement infrastructure is for most gas distribution networks very expensive and not feasible in practice. One promising approach for solving this challenge is the Nodal Point Load Observer, developed at Clausthal University of Technology, which emulates unknown offtakes, based on a mathematical model. This observation problem consists of an accurate determination of the inner state of incompletely instrumented natural gas distribution grids, based on the available measurement information. The knowledge of the inner state of the grid makes it possible to allocate a time series of a specific calorific value, and with that an amount of energy, to each offtake of the grid.

H. Wolf, S. Heinsch
DENSITY MEASUREMENTS OF LIQUID FUELS TO DETERMINE TEMPERATURE CONVERSION FACTORS FOR LEGAL METROLOGY

Worldwide there are great efforts to reduce the CO2 emission into the atmosphere by using fuels made from biomass. These biofuels are normally blended with fossil fuels.
For legal metrology the thermal expansion coefficient, the so-called temperature conversion factor, is of great importance to guarantee correct measurements of the fuel volume. Thus, the density of fossil fuels blended with biofuels was measured at the Physikalisch-Technische Bundesanstalt (PTB). Investigations were performed on mixtures of fossil petrol with ethanol and of fossil Diesel with biodiesel.
The volume concentration of the biofuels component varied between 0 % and 100 % in order to have data available for all possible mixtures. The data were measured in a temperature range between -10 °C and +50 °C.

Page 659 of 977 Results 6581 - 6590 of 9762