Traceability of the Hannover FG5X-220 to the SI units

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dc.identifier.uri http://dx.doi.org/10.15488/4210
dc.identifier.uri https://www.repo.uni-hannover.de/handle/123456789/4244
dc.contributor.author Schilling, Manuel ger
dc.contributor.author Timmen, Ludger ger
dc.date.accessioned 2018-12-19T05:52:22Z
dc.date.available 2018-12-19T05:52:22Z
dc.date.issued 2016-06-28
dc.identifier.citation Schilling, M.; Timmen, L.: Traceability of the Hannover FG5X-220 to the SI Units. In: Freymueller, J.T.; Sánchez, L. (Eds): International Symposium on Earth and Environmental Sciences for Future Generations (2016) (IAG Symposia ; 147), S. 69-75. DOI: https://doi.org/10.1007/1345_2016_226 ger
dc.description.abstract The absolute measurement of g is currently realized through the laser interferometric measurement of a free falling retro-reflector. The Micro-g LaCoste FG5X is a free-fall gravimeter with a laser interferometer in Mach-Zehnder configuration which uses simultaneous time and distance measurements to calculate the absolute value of g. Because the instrument itself contains the necessary working standards for precise time and length measurements, it is considered independent of external references. The timing is kept with a 10MHz rubidium oscillator with a stability of 5x10e-10. The length unit is realized by the laser interferometer. The frequency calibrated and iodine stabilized helium-neon laser has a wavelength of 633 nm and an accuracy of 2.5x10e-11. In 2012 the FG5-220 of the Institut für Erdmessung (IfE) was upgraded to the FG5X-220. The upgrade included a new dropping chamber with a longer free fall and new electronics including a new rubidium oscillator. The metrological traceability to measurement units of the Système International d’unités (SI unit) is ensured by two complementary and successive approaches: the comparison of frequencies with standards of higher order and the comparison of the measured g to a reference measured by absolute gravimeters defined as primary standards within the SI. A number of experiments to test the rubidium oscillator were performed. The oscillator showed a linear drift of 0.2x10e-3 Hz per month (= 0.3 nm/s² per month) in the first 18 months of use. A jump in the frequency of 0.01 Hz (=20 nm/s²) was revealed recently and the drift rate changed to 0.4x10e-3 Hz/month. ger
dc.language.iso eng ger
dc.publisher Cham : Springer
dc.relation.ispartof Freymueller J.T., Sánchez L. (Eds): International Symposium on Earth and Environmental Sciences for Future Generations. International Association of Geodesy Symposia, vol 147, pp. 69-75 (2016) ger
dc.relation.ispartofseries IAG Symposia;147
dc.rights Es gilt deutsches Urheberrecht. Das Dokument darf zum eigenen Gebrauch kostenfrei genutzt, aber nicht im Internet bereitgestellt oder an Außenstehende weitergegeben werden. ger
dc.subject absolute gravimetry eng
dc.subject frequency standard eng
dc.subject gravimeter comparison eng
dc.subject SI units eng
dc.subject metrology eng
dc.subject Absolutgravimetrie ger
dc.subject Frequenzstandard ger
dc.subject Gravimetervergleich ger
dc.subject SI Einheiten ger
dc.subject Metrologie ger
dc.subject.ddc 550 | Geowissenschaften ger
dc.title Traceability of the Hannover FG5X-220 to the SI units ger
dc.type bookPart ger
dc.type bookPart ger
dc.type conferenceObject ger
dc.type Text ger
dc.relation.doi 10.1007/1345_2016_226
dc.description.version acceptedVersion ger
tib.accessRights frei zug�nglich ger


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