Title :
Newton´s gravitational constant with uncertainty less than 100 ppm
Author :
Fitzgerald, M.P. ; Armstrong, T.R.
Author_Institution :
Gracefield Res. Centre, New Zealand Inst. of Ind. Res., Lower Hutt, New Zealand
fDate :
4/1/1995 12:00:00 AM
Abstract :
We have obtained a value for Newton´s gravitational constant (coverage factor of 1) of G=6.6656(6)×10-11 m3 kg-1·s-2 with a combined standard uncertainty of 95 ppm. The method is based on a torsion balance which is servocontrolled to constant angular position with an electrostatically induced torque balancing the gravitationally induced torque. This electrostatically induced torque is calibrated using an acceleration method
Keywords :
balances; fundamental law tests; gravitational constant; measurement errors; physical instrumentation control; servomechanisms; torque control; Newton´s gravitational constant; acceleration method; constant angular position; electrostatically induced torque; servocontrol; standard uncertainty; torsion balance; Acceleration; Accelerometers; Density measurement; Electrodes; Electrostatic measurements; Mirrors; Position measurement; Torque control; Torque measurement; Uncertainty;
Journal_Title :
Instrumentation and Measurement, IEEE Transactions on
