Abstract: A gravity anomalometer has dual units arranged in longitudinal alignment in a tube which in turn is maintained in substantially constant alignment with the center of gravity of the earth. Each unit has an upper electric member providing support for the mass and a similar lower electric member, with each member having an opening facing the opposite member. A single sensing mass initially supported in the upper member of each unit falls under the influence of gravity when the upper member is deenergized and is caught by the lower member when the latter is energized, after which the mass is returned to the upper field in a repeating cycle. Electronic means measure the rate of each fall of the mass. Since the mass in the upper unit is further from the earth's center of gravity than the mass in the lower unit the time consumed in a corresponding fall is less in the upper unit than in the lower unit. The difference in rate accordingly is made use of in determining the gravity gradient in a selected area.

Abstract: An instrument for detecting and making use of a charged particle located in a vacuum and contained by a cubic array of electrically chargeable electrodes is programmed to have the charged particle constantly in motion. A sensing means for each of three sets of plates becomes operative when the particle reaches a preset distance from the center of the array to trigger a pulse adapted to reverse the direction of movement of the particle. The instrument is one capable of detecting and measuring acceleration along three coordinate axes and rotational translations relative to inertial space and/or a gravity reference. It is also one for static and in-motion gravity and gravity gradient measurement. There is additionally a built-in detector of comparable accuracy capable of using the same particle to detect malfunction of the instrument.