Abstract: A passive radon surface flux monitor has a dome with an open base having a radial flange and a top opening where an electret can be threaded. Attached to and extending below the open base of the dome is a metal collar that supports the dome when placed on the ground. The collar holds a conductive screen against the radial flange. The conductive screen permits diffusion of gas including radon, thoron, and their daughter products into the dome. A thin paper diaphragm on the conductive screen prevents dust from entering the dome. Sealant seals the connection of the collar, screen, flange, and diaphragm to prevent lateral loss of radon. A collar is pressed partially into the ground at a suitable site and an electret is threaded into the top opening. After a time, the electret is removed and its change in voltage measured.

Abstract: A new type of radon progeny monitor called an electret radon progeny integrating sampling unit (E-RPISU) using an electret ion chamber to measure radon progeny concentration. A conventional 1 LPM particulate air sampling system is used to collect the radon progeny on a roughly 3.5 cm2 filter that is mounted on a side of an electret ion chamber such that the collected progeny are exposed to the inside of the chamber. Alpha radiation emitted by the progeny collected on the filter ionizes the air in the approximately 220 ml chamber. Ions of opposite polarity collect on the surface of the electret of suitable thickness and reduce its surface voltage. A specially built surface voltmeter is used to measure the electret voltage before and after sampling. The electret voltage drop that occurs during the sampling period is proportional to the time integrated progeny concentration. A similar unit with a screen in the place of filter is used to measure unattached progeny concentration.

Abstract: A gamma radiation compensated radon measurement system includes a housing and cooperating tube assembly that define a first, larger sensing volume and second, smaller sensing volume, each of which includes an electrically charged electret. When in its operative configuration, the first and second volumes are in communication with one another so that both volumes are exposed to the same radon concentration as well as the same gamma radiation. A partition separates the two sensing volumes so that ions formed in one sensing volume do not enter the other sensing volume. The two electrets are exposed to their respective sensing volumes to accumulate ions at different rates determined by the design characteristics of the two sensing volumes. The response characteristic of each electret/sensing volume combination is mathematically modelled and the radon and/or gamma concentration is be determined by simultaneously solving the characteristic equations for each electret/sensing volume combination.

Abstract: A small enclosed ion chamber with an electrostatically charged electret attached to the inner chamber wall. Filtered holes in the chamber permits radon in the ambient air in the chamber to enter or exit by diffusion. Positive or negative ions (depending on the polarity of the electret charge) formed in the chamber air by the passing of gamma radiation or X-rays move to and collect on the electret surface by virtue of its electrostatic attraction to ions of opposite polarity. These ions neutralize the ions of opposite polarity on the electret and cause a measurable reduction in its surface voltage which reduction is proportional to the dose of gamma and/or X-ray incidence on the chamber. The reduction of the electret surface voltage is used to calculate the dose of gamma or X-ray radiation incident upon the chamber during a known exposure period.

Abstract: A programmable controlled-exposure radon measurement system includes a radon detector of the type that is programmably inhibited or enabled at selected times to effect randon measurement. In the preferred embodiment, a radon detector of the type having an electret within a chamber is located at the test site and the container opened and closed to the ambient atmosphere at selected times to limit exposure to certain intervals during the day for a selected number of successive days. The container is opening by an actuator, such as an electro-actuator or a fluidic actuator, under the control of a programmable controller, such as a 7-day timer or a stored program controlled microprocessor. A fail-safe function is provided by which the radon detector is inhibited in the event of a power failure to preserve test data up to the time of the power failure.

Abstract: A sensitive radon monitor has a container with a flat bottom and an upwardly and outwardly extending truncated conical side wall terminating upwardly in a relatively large upper edge. A cover overlies the upper edge. The cover has a disk-shaped plate with holes in a circular arrangement. A filter is placed atop the disk and a retainer ring overlies a peripheral portion of the filter and the disk. A negatively charged electret is held against an underside of a central position on the disk, and a detector is held upward against the electret. A second positively charged electret lines the inside of the cup-shaped base. Ambient gases flow into and out of the container through the filter and through the holes in the cover disk. The filter removes liquid and solid particles flowing through the opening establish an equilibrium. Radon decays within the chamber and positively charged products of the decay are attracted and repelled toward the first electret and toward the detector.

Abstract: A seal has a fiber optic bundle which passes through a fastening device. One end of the bundle is exposed to a light source and the light pattern emitted from the other end is observed to determine whether anyone has tampered with the bundle or the fastening device. The bundle has end fittings which are received in intersecting passageways formed in a block and which pass through each other at the intersection. A flat portion of one end fitting passes through a one-way push nut integrally formed in the other end fitting to interlock the fittings. Alternatively, one fitting is press fit in the block and the other fitting is engaged by a one-way push nut mounted in an enlarged portion of its respective passageway. The shapes of the passageways correspond to the shapes of their respective fittings to prevent rotation of the fittings and to align the fittings for intermeshing with each other. The fibers in the bundle are divided and extend through divided passageways formed in one of the end fittings.

Abstract: Sources which emit tracer gas at a known constant rate are positioned throughout a building. Samples of air are collected in selected rooms with constant rate adsorbent samplers. Samplers are analyzed in a laboratory to determine the tracer gas concentration during the period sampled, which concentration is compared to the known volume of the building to determine air infiltration rates. The tracer gas emission rate is rendered independent of room temperature by allowing the gas to escape through specially designed orifices which automatically open and close in response to changes in temperature. In one design, an orifice is formed in a material which expands and contracts with variations in temperature surrounded by a second, less elastic material. In another design, the area of an orifice is changed by a needle valve imbedded in a material which expands and contracts with temperature variations to move the needle in and out of the orifice.

Abstract: Locations of buried deposits are determined by detecting the presence of Pb214, Bi214, Po214, Pb210, Bi210 and Po210 in solutions obtained by chemically leaching these elements from rocks and soil. Polonium from the solution is plated on silver foil planchets. Alpha sensitive films are exposed to the alpha decay of Po214 and Po210 by contacting the films with the planchets. The films, when etched, reveal the damage caused by the passage of the high energy alpha particles. Alpha damage as a function of sample size, volume of solution used, planchet, foil or film area and exposure times measures concentration of Po214 and Po210 in the sample. Anomalus concentrations suggest presence of buried deposits containing uranium. Similar anomalus concentrations of alpha damage from Bi212 and Po212 formed in films exposed to foils or planchets plated from leached solutions containing Pb212, Bi212 and Po212 suggest deposits containing thorium.

Abstract: Locations of buried deposits containing uranium are determined by detecting the presence of Pb214, Bi214, Po214, Pb210, Bi210 and Po210 in solutions obtained by chemically leaching these elements from rocks and soil. Alpha sensitive films are exposed to the alpha decay of Po214 and Po210. The films, when etched, will reveal the damage caused by the passage of the high energy alpha particles. Alpha damage as a function of sample size, volume of solution used, film area and exposure measures concentration of Po214 and Po210 in the sample. Anomalous concentrations suggest presence of buried deposits containing uranium. Similar anomalous concentrations of alpha damage from Bi212 and Po212 formed in films exposed to foils or planchets from leach solutions containing Pb212, Bi212 and Po212 suggest deposits containing thorium. Plotting normalized alpha damage (numbers of alpha damage per gram, per square mm., per hour) and sample locations suggest mineral deposit locations.

Abstract: Self-monitoring seals have ends of fiber optic bundle loops mounted in stressed tamper resistant containers. A battery operates microelectronics to change a display in predetermined sequence. Tampering with the container or interrupting or changing the light transmission through the fiber optic bundle disrupts the predetermined display sequence.

Abstract: Locations of buried deposits containing uranium are determined by detecting the presence of Pb214, Bi214, Po214, Pb210, Bi210 and Po210 in solutions obtained by chemically leaching these elements from rocks and soil. Alpha sensitive nuclear emulsions are exposed to the alpha decay of Po214 and Po210. The emulsions are developed to display alpha tracks. Alpha track population as a function of sample size, volume of solution used, emulsion area and exposure measures concentration of Po214 and Po210 in the sample. Anomalus concentrations suggest presence of buried deposits containing uranium. Similar anomalus concentrations of alpha tracks from Bi212 and Po212 formed in emulsions exposed to leach solutions containing Pb212, Bi212 and Po212 suggest deposits containing thorium. Plotting normalized alpha track population (numbers of alpha tracks per gram, per square mm., per hour) and sample locations suggest mineral deposit locations.

Abstract: A fiber optic seal having a block with similar fiber spreading inserts and similar fiber combining inserts which terminate in rectangular facial fiber openings. The block is placed on alignment lugs and a rectangular reticle is precisely moved by a micrometer in front of the light source to illuminate the one group of fiber ends. The second group of ends in the block is observed through an observing device mounted in an angle in the housing parallel to a handle which includes a power source.

Abstract: A fiber optic bundle is placed through an object to be sealed. Ends of the fibers are spread and threaded through one another in a random dispersion, disorienting the fibers. Randomly reoriented ends are regathered and clamped. A moveable reticle at a light input termini of the fibers creates unique identifiable patterns at the output end of the fibers.

Abstract: The invention is directed to a security device which detects tampering with secured closure. A fiber optic bundle is looped through a closure and secured at opposite ends of the bundle to a collar. After installation, light is passed through the fiber optics and they generate a particular pattern at a viewing end of the collar. If there is any tampering with the enclosure, the individual fiber optics will be disturbed or cut. Subsequent viewing of the fiber optics will generate a different viewing pattern indicating that tampering has occurred.

Abstract: A fiber optic seal assembly tool has a stripper for stripping a predetermined length of tubing from an end of a fiber optic bundle. The stripped end is inserted in a seal block and the block is gripped in a hand tool. An actuating lever is squeezed, biasing bundle clamps closed, and sliding a grooved anvil toward the block to press a collet chuck which holds the fiber ends into the block. When the collet is pressed into the block, ends of the fibers are sheared by a knife which moves in the anvil opening.