Abstract: A system for measuring the density of a hydrostatic liquid in a container includes a pair of serially connected pressure sensors mounted in the liquid, a constant volume gas flow source connected to an inlet of one pressure sensor, a second pressure sensor connected to the outlet of the first pressure sensor, and a vent is connected between the second pressure sensor outlet and the atmosphere. A gauge or pressure transducer in the gas conduit from the source to the first pressure sensor provides pressure measurements that can be used to determine the level of liquid in the container and a differential pressure transducer across the first pressure sensor can be used to determine density of the liquid. Exhaust gas from the pressure sensors is passed to the atmosphere through a pressure buffering device in one construction of the system. The pressure sensors each have a rigid body with a generally circular resting surface over which a flexible diaphragm member is positioned.

Abstract: A well logging instrument has a plurality of contact arms which are forced against the sidewall of the borehole. The contact arms are pivotally attached to a first collar fixed to a central shaft and are pivotally attached to a second collar slidably mounted on the central shaft. Radial movement of the center of the contact arms moves a slidable collar member over an electrical coil assembly emitting an alternating magnetic flux field. The movement of the slidable collar over the electrical coil assembly alters the eddy current loading of a coil. The position of the contact arms and thus the position of the slidable collar attached thereto can be measured by detecting the eddy current loading of the coil.

Abstract: Apparatus for taking a sample of earth formations surrounding a borehole. A core sampling projectile is provided which has a core-taking barrel with a frontal cutting edge and is releasable secured to a base member of relatively more mass than the barrel. The base member has an enlarged outer diameter annular abutment thereby limiting the depth of penetration of the core-taking barrel to a predetermined distance.