New Measurements of G Using the Measurement Standards Laboratory Torsion Balance

This is the authors' abstract. We don't add key points for this paper.

This Letter presents the results of a series of measurements of the Newtonian gravitational constant G using the compensated torsion balance developed at the Measurement Standards Laboratory. Since our last published result using the torsion balance in the compensated mode of operation [Meas. Sci. Technol. 10, 439 (1999)], several improvements have been made to reduce the uncertainty in the final result. The new measurements have used both stainless steel and copper large masses. The values of G for the two sets of masses are in good agreement. After combining all of the measurements we get a value of $G=6.673 87(0.000 27)×{}{10}^{{-}11} {m}³ {kg}^{{-}1} {s}^{{-}2}$. This new value is 5 parts in ${10}⁵$ smaller than our previous published values.