Determination of the gravitational constant at an effective interaction distance of 112 m

The Newtonian gravitational constant has been determined at an effective interaction distance of 112 m. A high-precision balance was used to compare the weights of two 1-kg stainless stell masses located above and below the variable water level of a pumped-storage lake. Water-level changes up to 43 m produced a maximum weight difference of 1290 μg, which could be measured with a resolution of <1 μg. The data yield a value for the gravitational constant G of (6.6700±0.0054)×${10}^{\mathrm{-}11}$ ${\mathrm{m}}^3$ ${\mathrm{kg}}^{\mathrm{-}1}$ ${\mathrm{s}}^{\mathrm{-}2}$ (1σ), in agreement with laboratory determinations. New limits for the strength of possible new intermediate-range forces are placed.