Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Results of the Sixth International Comparison of Absolute Gravimeters, ICAG-2001


David B. Newell


The Sixth International Comparison of Absolute Gravimeters was held from 2 July to 28 August 2001 at the Bureau International des Poids et Mesures (BIPM), S'vres. Seventeen absolute gravimeters were used to make measurements at five sites of the BIPM gravity network. The vertical gravity gradients at the sites and the ties between them were also measured using seventeen relative gravimeters. For the first time the ties were also measured using the absolute gravimeters. Various methods of processing the absolute and relative data were tested to calculate the results. The final results of the ICAG-2001 are presented. The acceleration due to gravity at a height of 0.90 m is given as (980 925 701.2 ' 5.5) 'Gal and (980 928 018.8 ' 5.5) 'Gal for sites A and B, respectively, calculated using a combined adjustment of the absolute and relative data.


Gravity, absolute Gravimeters, relative gravimeters, length standards and time standards


Newell, D. (1970), Results of the Sixth International Comparison of Absolute Gravimeters, ICAG-2001, Metrologia (Accessed May 21, 2024)


If you have any questions about this publication or are having problems accessing it, please contact

Created August 26, 2016, Updated January 27, 2020