MEASURAND : Free-fall acceleration
NOMINAL VALUE : 9.81 m/s2
MEASURAND : Free-fall acceleration
NOMINAL VALUE : 9.81 m/s2
Degrees of equivalence: Dk and expanded uncertainty Uk (k = 2), both expressed in µGal
Results are presented under A4 printable format in Summary Results (PDF file).
| Metrology area, Sub-field | Mass and related quantities, Gravity |
| Description | Free-fall acceleration |
| Time of measurements | 2009 |
| Status | Approved for equivalence |
| Final Reports of the comparisons | |
| References | |
| Measurand | Free-fall acceleration: 9.81 m/s2 The non-SI unit "Gal" is normally used in this field: 1 Gal = 10-2 m/s2 |
| Transfer device | Comparison of gravimeters at the BIPM site |
| Comparison type | Key Comparison |
| Consultative Committee | CCM (Consultative Committee for Mass and Related Quantities) |
| Conducted by | CCM (Consultative Committee for Mass and Related Quantities) |
| Comments | This key comparison was carried out by a subset of participants in the International Comparison of Absolute Gravimeters (ICAG). ICAG-2009 took place at the BIPM in September and October 2009. Results published on 13 June 2012 Free-fall acceleration |
| Pilot institute |
BIPM
Bureau International des Poids et Mesures BIPM - International Organization |
| Contact person | E. F. Arias +33 (0) 1 45 07 70 76 |
| Additional |
| Pilot laboratory | |
|---|---|
| BIPM |
Bureau International des Poids et Mesures, BIPM - International Organization, N/A |
| BEV |
Bundesamt für Eich- und Vermessungswesen, Austria, EURAMET |
| CMS |
ITRI Center for Measurement Standards, Chinese Taipei, APMP |
| FGI |
Finnish Geospatial Research Institute, Finland, EURAMET |
| KRISS |
Korea Research Institute of Standards and Science, Korea, Republic of, APMP |
| LNE-SYRTE |
Observatoire de Paris/Systèmes de Référence Temps-Espace; now: Observatoire de Paris/Laboratoire Temps Espace (LNE-OP), France, EURAMET |
| METAS |
Federal Institute of Metrology, Switzerland, EURAMET |
| NIM |
National Institute of Metrology, China, APMP |
| NMIJ AIST |
National Metrology Institute of Japan, Japan, APMP |
| NRC |
National Research Council, Canada, SIM |
| UME |
TÜBITAK Ulusal Metroloji Enstitüsü, Türkiye, EURAMET |
| VNIIM |
D.I. Mendeleyev Institute for Metrology, Rosstandart, Russian Federation, COOMET |
| VUGTK/RIGTC |
Research Institute of Geodesy, Topography and Cartography, Czechia, EURAMET |
This page proposes print-out on A4 paper (portrait) of the comparison details (best printed out using a black and white printer).
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MEASURAND : Free-fall acceleration
NOMINAL VALUE : 9.81 m/s2
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A weighted least-square adjustement is applied to the set of measurements obtained from absolute gravimeters AG(k) at Stations j, gjk, with standard uncertainty ujk, in order to evaluate the gravity value Gj at each Station j, as well as the offset Dk for absolute gravimeter AG(k), using the following model:
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| The degree of equivalence of absolute gravimeter AG(k) is given by a pair of terms: Dk and Uk, its expanded uncertainty with coverage factor equal to 2, obtained from the ujk values, both expressed in µGal. |
MEASURAND : Free-fall acceleration
NOMINAL VALUE : 9.81 m/s2
AG(k) : absolute gravimeter of Laboratory k
Station j : designation of the BIPM station where the measurement was carried out
gjk : gravity value at Station j and height Hjk after substraction of 980 900 000 µGal
ujk : combined standard uncertainty of gjk
The comparison was performed in 2009
Each participant communicated gravity measurements for three of the five stations used
