Patents Assigned to Terradex Corporation
  • Patent number: 4518860
    Abstract: A compact low cost track registration detector for radon gas and radon daughter products includes a housing with a removable closure cap for retaining a strip of track registration material having the property of forming damage tracks along paths traversed by alpha particles. The strip is retained within the housing by integrally formed upstanding ribs located closely adjacent diametrically opposite inner side wall portions of the housing, a first set of ribs forming a pedestal support and second set of longer ribs providing transverse support. A microporous filter impervious to particles and radon daughter products admits only radon gas to the interior of the housing. The apertured closure cap has a central solid portion providing a radiation shield for the upper surface of the strip to enable the lower exposure surface to be readily distinguished after the detector has been retrieved from an exposure site.
    Type: Grant
    Filed: October 19, 1982
    Date of Patent: May 21, 1985
    Assignee: Terradex Corporation
    Inventors: H. Ward Alter, Richard A. Oswald
  • Patent number: 4338523
    Abstract: A low cost disposable radiation detector of the track registration material type having a substrate layer with a strip of the track registration material removably attached thereto. The track registration material is removably attached to the substrate by a top layer having an aperture formed therein and at least one tab portion adjacent the aperture and bendable out of the top layer to overlap a portion of the strip of track registration material for retaining the strip in the aperture.
    Type: Grant
    Filed: April 11, 1980
    Date of Patent: July 6, 1982
    Assignee: Terradex Corporation
    Inventor: H. Ward Alter
  • Patent number: 4065972
    Abstract: A method and apparatus for collecting gas samples associated with underground minerals. A plurality of small gas sample containers are planted in an inverted position in shallow holes in the surface of the earth in a predetermined pattern, and upwardly migrating gases associated with the underground minerals being sought are collected in the containers for a predetermined time period, to obtain a time-integrated representation of the amount of one or more gases of interest migrating to the surface over that time period. Two types of containers are alternately employed: A total gas sample container in which all upwardly migrating gases are admitted into a sealed compartment at a preselected flow rate; and a specific gas sampler container in which strips of detector material which are sensitive to predetermined specific gaseous substances are mounted within the inverted container and exposed to the upwardly migrating gases over the predetermined time interval.
    Type: Grant
    Filed: May 24, 1976
    Date of Patent: January 3, 1978
    Assignee: Terradex Corporation
    Inventors: Fred F. Holub, H. Ward Alter
  • Patent number: 4064436
    Abstract: A method and apparatus are described for reducing or removing the background noise caused by thoron gas (.sup.220 Rn) in uranium exploration conducted by the detection of radon gas (.sup.222 Rn) emanating from the ground. This is accomplished by the use of a number of alpha particle detectors, each of which is disposed in a protective enclosure. A permselective membrane, which permits, but selectively retards, the passage therethrough of gases is disposed in the path to be traversed before such gases can reach the alpha particle detector. The retarding influence of the membrane should be sufficient to make the concentration of thoron inside the enclosure small relative to the concentration of thoron outside the enclosure. The influence of the membrane on radon should be negligible, i.e. the randon concentration inside and outside the enclosure should be substantially equal.
    Type: Grant
    Filed: August 18, 1976
    Date of Patent: December 20, 1977
    Assignee: Terradex Corporation
    Inventor: William J. Ward, III
  • Patent number: 4063087
    Abstract: A method and apparatus are described for reducing or removing the background noise caused by thoron gas (.sup.220 Rn) in uranium exploration conducted by the detection of radon gas (.sup.222 Rn) emanating from the ground. This is accomplished by the use of a number of alpha particle detectors, each of which is disposed in a protective enclosure. A barrier which permits, but deliberately retards, the passage therethrough of gases is disposed in the path to be traversed before such gases can reach the alpha particle detector. The increase in the transit time made necessary by requiring soil gases to move through the barrier should be sufficiently long to allow the decay of most of the thoron, thereby eliminating its contribution to the total signal reflected at the detector.
    Type: Grant
    Filed: August 18, 1976
    Date of Patent: December 13, 1977
    Assignee: Terradex Corporation
    Inventor: Robert L. Fleischer
  • Patent number: 3987677
    Abstract: A plurality of gas sample collecting containers are distributed in a predetermined pattern from a vehicle. The containers are cup shaped but weighted so that the open end sinks first and engages the subaqueous earth laer. Gas migrating upwardly through the earth is caught by the inverted cup. The gas sample may be either collected in a separate container or exposed to a detector material located above the expected water level. The sample collecting containers may be retrieved by means of marker floats, magnetic grappling devices or self actuated flotation devices.
    Type: Grant
    Filed: January 30, 1976
    Date of Patent: October 26, 1976
    Assignee: Terradex Corporation
    Inventor: H. Ward Alter