New Developments In Underground Microgravity

Underground gravity observations in deep coal mines using the conventional<br>gravity meter LaCoste-Romberg Model D which has been adapted to the fire<br>damp regulations, can be accurate to ± 3 ugal. For underground<br>determination of the vertical gradient of gravity the LaCoste-Romberg meter<br>is used together with a specially designed measuring tower. Using this<br>equipment an accuracy in tower gradient observations of ± 30E was obtained.