The 8th International Comparison of Absolute Gravimeters 2009: the first Key Comparison (CCM.G-K1) in the field of absolute gravimetry

TLDR

ICAG2009, held at BIPM in September–October 2009, was the first key comparison under the CIPM Mutual Recognition Arrangement, involving gravimeters from national metrology institutes and their designated institutes. The study aimed to secure international acceptance of the participating institutes’ measurement capabilities under the CIPM Mutual Recognition Arrangement. The comparison comprised a key comparison (CCM.G‑K1) organized by CCM, with a parallel pilot study to include additional non‑MRA gravimeters. CCM.G‑K1 produced an accurate, SI‑traceable gravity reference that serves as a global basis for geodetic, geophysical, and metrological observations.

Abstract

The 8th International Comparison of Absolute Gravimeters (ICAG2009) took place at the headquarters of the International Bureau of Weights and Measures (BIPM) from September to October 2009. It was the first ICAG organized as a key comparison in the framework of the CIPM Mutual Recognition Arrangement of the International Committee for Weights and Measures (CIPM MRA) (CIPM 1999). ICAG2009 was composed of a Key Comparison (KC) as defined by the CIPM MRA, organized by the Consultative Committee for Mass and Related Quantities (CCM) and designated as CCM.G-K1. Participating gravimeters and their operators came from national metrology institutes (NMIs) or their designated institutes (DIs) as defined by the CIPM MRA. A Pilot Study (PS) was run in parallel in order to include gravimeters and their operators from other institutes which, while not signatories of the CIPM MRA, nevertheless play important roles in international gravimetry measurements. The aim of the CIPM MRA is to have international acceptance of the measurement capabilities of the participating institutes in various fields of metrology. The results of CCM.G-K1 thus constitute an accurate and consistent gravity reference traceable to the SI (International System of Units), which can be used as the global basis for geodetic, geophysical and metrological observations of gravity. The measurements performed afterwards by the KC participants can be referred to the international metrological reference, i.e. they are SI-traceable.