Abstract: A borehole logging method comprises processing density measurements taken by at least one probe at intervals along a borehole to determine the gravitational effects of geologic formations intersected by the borehole; and removing the determined gravitational effects from gravity measurements taken by at least one probe at intervals along the borehole to determine the gravitational efforts of geologic formations from the borehole.

Abstract: An apparatus for measuring gravity in a small diameter borehole comprises a pressure tube and at least one pendulum gravity sensor accommodated by the pressure tube. The gravity sensor comprises a pendulum and circuitry to monitor generally continuously the swing period and amplitude of the pendulum.

Abstract: An apparatus for determining the orientation of a borehole at a point along the borehole, includes a tiltmeter for measuring the inclination of the borehole relative to the vertical, a vector magnetic sensor for measuring the amplitude of the component of the Earth's magnetic field along the axis of the borehole, and means for computing the orientation of the tubular sonde from the measurements of inclination and amplitude of the component of the Earth's magnetic field aligned with axis of the sonde.

Abstract: Apparatus for conducting geophysical surveys comprising a multiplicity of intelligent electrodes provided on a multi-conductor cable, for receiving a command signal in response to which predetermined electrodes are connected to selected conductors in the cable. Each intelligent electrode is identical in all respects, including its programming, resulting in simplified construction of the cable and easy replacement of the intelligent electrodes. Instead of assigning a unique address code to each switch in a series of take-outs on a multi-conductor cable, each electronic switch is programmed with the same address code. That is, each switch is programmed to be activated when it receives a code command that, for example, is prefaced with a particular address, e.g. the number 1. The second part of the code (y) instructs the switch as to which conductor in the multi-conductor cable is to be connected to the local electrode at the location of the switch.

Abstract: A method of attaching a first member of one of quartz and a ceramic to a metal member. The method includes creating a hole in the metal member, the hole being smaller in size than the size of the first member over a temperature range, heating the metal member to a temperature sufficient to expand the hole to allow insertion of the first member in the hole, inserting a portion of the first member into the hole, and cooling the metal member to form a joined structure of the first member and the metal member.

Abstract: A method and apparatus are provided for surveying a given region for the presence of ferromagnetic items and other sources of magnetic field disturbance on or under the ground, such as pipelines and wellheads, etc. An array of magnetic field sensors, mounted on a suitable framework, is passed over the region while the sensors emit appropriate signals, whereupon the signals are used to determine the total magnetic field and its gradients, with respect to distance, a) in the direction of movement, b) horizontally transverse to the direction of movement, and c) in the vertical direction. The total field and its gradients are interpreted to show the presence or absence of sources of magnetic field disturbance items, as well as to discriminate between various categories of such sources.

Abstract: Apparatus for remotely determining the amount of current I flowing in a long, linear conductor, comprising a first sensor for measuring at a first location a magnetic field H arising due to current flow, a second sensor for measuring at a second location the same magnetic field H, a mounting mechanism for fixing the position of the first and second sensors in an unchanging, spaced-apart mutual configuration, calculating apparatus for calculating the vertical gradient H′ of the magnetic field on the basis of measurements made by the sensors, and further calculating apparatus for determining the current I on the basis of the equation I=H2/H′ where k is a constant.

Abstract: Apparatus for preconcentrating trace amounts of organic vapors in a sample of air for subsequent detection, comprising a metallic substrate; a thin film of fullerenes deposited on the metallic substrate for adsorbing the organic vapors on the thin film of fullerenes, thereby preconcentrating the organic vapors; and apparatus for heating the metallic substrate to a predetermined optimum temperature for desorbing the vapors from the thin film of fullerenes to form desorbed organic vapors for subsequent detection.

Abstract: The interference of ozone in the determination of nitrogen dioxide determinations by luminol chemiluminescence is eliminated by first passing the gas sample into contact with a selective reducing agent for ozone, particularly antimony trioxide.

Abstract: Chemiluminescence is detected in a luminol solution free of metal ions flowing through a porous material to indicate the presence of certain nitrogen-containing gases. Continuous monitoring of atmosphoric gases is possible through use of the described methods and related apparatus.

Abstract: We have discovered that certain photoluminescent minerals of zinc, fluorine, tungsten, molybdenum, mercury and other elements which may naturally occur at the surface of the earth can be selectively detected in the presence of most other photoluminescent minerals and organic materials which are likely to occur at the earth's surface. The basis of selective detection is the discovery that the lifetimes of photoluminescent emission of materials in the latter class are much shorter than the lifetimes of photoluminescent emission of materials in the former class. This invention utilizes this discovery in the detection of minerals of uranium, zinc, lead, fluorine, tungsten, molybdenum, mercury and other elements.

Abstract: A rotating target contains an appropriately shaped section of photoelectric material which detects the position of a beam of light which is incident on the target. The position of the beam is determined in terms of its distance from the center of rotation of the target and by its angular position relative to the vertical. The vertical direction is simultaneously determined relative to the rotating target using a gravity operated reference.

Abstract: This invention relates to electromagnetic mapping wherein magnetic fields of two or three different and normally audio frequencies may be transmitted or received efficiently using induction coils with the same orientation and essentially the same spatial location. Flat, air cored coils are used and are overlapped so as to have essentially zero mutual inductance between pairs.

Abstract: This invention is a method that uses the previously undiscovered fact that the phosphorescent lifetime of the uranyl ion at very dilute concentrations in an aqueous solution is anomalously long in comparison to that of other commonly-occurring phosphorescent species, wherein the uranyl ions in the low concentration sample are excited by projecting electromagnetic energy into the sample, terminating the projection of electromagnetic energy into the sample and measuring the characteristics of the decaying uranium phosphorescence after termination of the incident electromagnetic radiation.

Abstract: A method of detecting uranium compounds in an aqueous sample, containing uranium compounds that phosphoresce in response to ultraviolet light and other compounds which luminesce but have a shorter lifetime of phosphorescence than uranium compounds comprising the steps of increasing the phosphorescent characteristics of the uranium compounds and simultaneously diminishing the quenching efficiency of interfering ions in the sample by adding a polyphosphate compound and a buffer; projecting ultraviolet light into the sample; terminating said projection of ultraviolet light into the sample; measuring intensity of the decaying uranium phosphorescence at a time delay after the termination of the ultraviolet light, the time delay being longer than the time for luminescence due to materials other than uranium compounds possibly in the sample to substantially decay.

Abstract: A method of geophysically prospecting a polarizable medium by measuring induced polarization effects wherein the medium is inductively polarized by a time varying current in an induction coil that varies with respect to time unidirectionally to maintain a unidirectional current flow in the medium for a first period and then does not vary with respect to time for a second period and wherein the induced polarization effects caused by the unidirectional current flow in the first period are measured during the second period.