Gravity Reference Systems - German Gravity Reference Systems -
European Gravity Reference Systems - Global Gravity Reference
Systems The free fall of a test mass is recorded with high
accuracy. In order to minimize non-gravitational disturbing
influences, such as air drag, buoyancy etc. the test mass moves
in an evacuated chamber. The "absolute" determination of the
gravitational acceleration results from the use of physical
standards of highest accuracy: A rubidium standard for time
measurement and an iodine-stabilized laser for length
measurement. By means of the absolute gravimeter FG5
(manufacturer: Micro-g LaCoste Inc., USA), which represents the
currently best possible technical development status, measuring
accuracies of ±20…30 nm/s2 (±2…3 µGal) can be obtained under
favorable ambient conditions. This corresponds to a relative
accuracy of ±2…3 x 10-9. BKG applies the absolute gravimeter A10
with a measuring accuracy of ±100 nm/s2 made by the same
manufacturer for field measurements. Absolute gravimeter