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Vitushkin L.,Bureau International des Poids et Mesures BIPM | Jiang Z.,Bureau International des Poids et Mesures BIPM | Robertsson L.,Bureau International des Poids et Mesures BIPM | Becker M.,TU Darmstadt | And 36 more authors.
International Association of Geodesy Symposia | Year: 2010

The International Comparison of Absolute Gravimeters ICAG-2005 was held at the Bureau International des Poids et Mesures (BIPM), Sèvres, France in September 2005. The organization of ICAG-2005, measurement strategy, calculation and presentation of the results were described in a technical protocol pre-developed to the comparison. Nineteen absolute gravimeters carried out 96 series of measurements of free-fall acceleration g at the sites of the BIPM gravity network. The vertical gravity gradients were measured by relative gravimeters. For the first time the budgets of uncertainties were presented. The g-values for the sites A and B of the BIPM gravity network at a height of 0.90 m are (980,925,702.2 ± 0.7) μGal and (980,928,018.5 ± 0.7) μGal, respectively. This result is in a good agreement with that obtained in ICAG-2001. © Springer-Verlag Berlin Heidelberg 2010.

Kocadag M.,Vienna University of Technology | Exler V.,Vienna University of Technology | Christopher B.-S.,Vienna University of Technology | Baumgartner A.,University of Natural Resources and Life Sciences, Vienna | And 4 more authors.
Applied Radiation and Isotopes | Year: 2017

137Cs and 40K in soil, vegetation and flesh of wild boar samples from Austrian and Bavarian regions were investigated by gamma-ray spectrometry and 90Sr in bones of wild boar with Liquid Scintillation Counting (LSC) after radiochemical separation. The soil core profiles revealed that 70-97% of the soil caesium content is still accumulated in the 0-10cm soil depth. From all vegetation samples the mushrooms, particularly the bay boletus showed the highest 137Cs contamination. The activity concentration of 137Cs in muscle tissue of boar ranged from 14.9±1.5Bq/kg (Bavaria) to 4711±377Bq/kg (Lower Austria). In the bones of wild boars, 90Sr activity concentration ranged from 1.4±0.2Bq/kg (Bavaria) to 70.3±10.5Bq/kg (Upper Austria). © 2017.

Francis O.,University of Luxembourg | van Dam T.,University of Luxembourg | Germak A.,INRIM - Istituto Nazionale di Ricerca Metrologica | Amalvict M.,Ecole et Observatoire des science de la Terre EOST | And 41 more authors.
International Association of Geodesy Symposia | Year: 2010

The second international comparison of absolute gravimeters was held in Walferdange, Grand Duchy of Luxembourg, in November 2007, in which twenty absolute gravimeters took part. A short description of the data processing and adjustments will be presented here and will be followed by the presentation of the results. Two different methods were applied to estimate the relative offsets between the gravimeters. We show that the results are equivalent as the uncertainties of both adjustments overlap. The absolute gravity meters agree with one another with a standard deviation of 2 μgal (1 gal = 1 cm/s2). © Springer-Verlag Berlin Heidelberg 2010.

Hausmann H.,Vienna University of Technology | Hausmann H.,Central Institute for Meteorology and Geodynamics ZAMG | Krainer K.,University of Innsbruck | Bruckl E.,Vienna University of Technology | Ullrich C.,Federal Office of Metrology and Surveying BEV
Austrian Journal of Earth Sciences | Year: 2012

In this study we use a concept based on three geophysical methods (Ground-penetrating radar/GPR, seismic refraction, gravimetry) to provide new insight into the internal structure, ice content and dynamics of the two active rock glaciers Ölgrube and Kaiserberg. Both rock glaciers are located in side valleys of the Kauner Valley (Ötztal Alps, Austria) and consist of debris derived from orthogneiss, paragneiss and mica schist. At both rock glaciers we determined a 4 - 6 m thick debris layer at the surface (active layer), underlain by 20 - 30 m of ice-rich permafrost, and 10 - 15 m of ice-free sediments. The average depth to the bedrock was found in 35 - 50 m. Estimated volumetric ice contents vary between 40 and 60% based on our field measurements. Structural and physical parameters derived from the mentioned surface based geophysical methods are used to explain the dynamics of the rock glaciers. From the two rock glaciers that were investigated in this study and one additional rock glacier, which was investigated by applying the same methodology in an earlier study, we found a parameter that describes their creep behaviour and shows that the three geophysical models are conclusive. Concerning the dynamics of these active rock glaciers, the data indicate that a reduction of the ice content causes an increase of internal friction, lower seismic P-wave velocities, and higher bulk densities. In order to keep a degrading rock glacier in motion a thickening is required. The GPR-reflection patterns of the permafrost layer and their relation to the structural and physical parameters primarily reveal that long reflectors parallel to the surface are found in regions with high P-wave velocity and low density, indicating zones with high ice content.

Jiang Z.,Bureau International des Poids et Mesures BIPM | Francis O.,University of Luxembourg | Vitushkin L.,Bureau International des Poids et Mesures BIPM | Palinkas V.,Research Institute of Geodesy | And 35 more authors.
Metrologia | Year: 2011

The Bureau International des Poids et Mesures (BIPM), Sèvres, France, hosted the 7th International Comparison of Absolute Gravimeters (ICAG) and the associated Relative Gravity Campaign (RGC) from August to September 2005. ICAG 2005 was prepared and performed as a metrological pilot study, which aimed: To determine the gravity comparison reference values; To determine the offsets of the absolute gravimeters; and As a pilot study to accumulate experience for the CIPM Key Comparisons. This document presents a complete and extensive review of the technical protocol and data processing procedures. The 1st ICAG-RGC comparison was held at the BIPM in 1980-1981 and since then meetings have been organized every 4 years. In this paper, we present an overview of how the meeting was organized, the conditions of BIPM gravimetric sites, technical specifications, data processing strategy and an analysis of the final results. This 7th ICAG final report supersedes all previously published reports. Readings were obtained from participating instruments, 19 absolute gravimeters and 15 relative gravimeters. Precise levelling measurements were carried out and all measurements were performed on the BIPM micro-gravity network which was specifically designed for the comparison. © 2011 BIPM & IOP Publishing Ltd.

Bosco G.C.,INRIM - Istituto Nazionale di Ricerca Metrologica | Garcocz M.,Federal Office of Metrology and Surveying BEV | Lind K.,Norwegian Metrology Service | Pogliano U.,INRIM - Istituto Nazionale di Ricerca Metrologica | And 4 more authors.
IEEE Transactions on Instrumentation and Measurement | Year: 2011

A comparison of the phase error of existing shunts for currents between 10 and 100 A and frequencies from 500 Hz to 100 kHz has been organized. Measurement processes were performed at Istituto Nationale di Ricerca Metrologica on some shunts using the first prototype of a new type of a phase comparator and a step-up method for data processing. Results of the relative measurement processes have shown good repeatability. The method for evaluation of reference values was based on similar shunts and suitable assumptions and derived by extrapolation. For the type of resistance elements employed in these shunts, the derivation of the reference is not very accurate and still needs to be improved. © 2006 IEEE.

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