Abstract: An electronic marker locator with a digital architecture for providing accurate and consistent estimation of the signal strength is presented. The marker locator includes a Digital Phase-Locked Loop (DPLL) structure. The electronic marker locator transmits known and adjustable frequency bursts corresponding to the markers to be located while synchronously capturing the signals returned from the markers.

Abstract: In a method of identifying a passive electromagnetic signal emitted from an underground utility, a portable above-ground antenna is disposed at a location at which the passive electromagnetic signal is expected. Measurement signals are received from the antenna corresponding to electromagnetic signals received by the antenna. The measurement signals are measured at a plurality of different frequency bands within a measurement frequency range expected to include a frequency of the passive electromagnetic signal, and at least one of the plurality of frequency bands is selected based on a predetermined criteria applied to the measurements.

Abstract: Systems and methods presented herein are generally directed to the location and/or identification of a circuit within a circuit. In one embodiment, a transmitter is configured for inducing a signal upon a circuit (e.g., power lines, communication lines, lighting circuits, etc.) to identify it from other circuit lines. The signal may be induced upon an individual element of the circuit through direct contact. A receiver may receive a radiated component of the signal from a distal point on the circuit to acquire the signal induced thereon and determine a strength of the signal received. Based on the received signal component, the receiver may determine location, configuration, and/or identification of the circuit from which the radiated signal is being received.

Abstract: An object of the present invention is to provide an object detector which can intuitively show detection information and facilitate the observation of a detected surface covered by a display screen. The detector includes a housing, a detecting circuit for detecting a hidden object behind a surface, which is arranged in the housing and includes at least one detecting element, a power supply electrically connected to the detecting circuit, and a display device 10 electrically connected to the detecting circuit, which includes a display screen attached to the housing. The display screen is transparent in a non-display stat while an information-displaying section of the display screen is opaque in a display state. By using such an object detector, an operator can obtain an intuitive indication from the object detector and simultaneously observe the marking condition on a section of a detected surface covered by a display screen during a detection operation.

Abstract: A boring tool is moved through the ground in a region which includes at least one electrically conductive in-ground line and which is subject to static magnetic fields including the magnetic field of the earth.

Abstract: A system for selectively grounding each of a plurality of short-haul buried utility conveyances coupled to a common long-haul buried utility conveyance to enable a conveyance locating signal transmitted through the long-haul conveyance to travel from the long-haul utility conveyance to a selected short-haul utility conveyance. The system includes a first optical switch for selecting each of the plurality of short-haul utility conveyances to be grounded, where the first optical switch is adapted to receive an optical signal and selectively output the optical signal on one of a plurality of optical fibers; and a second optical switch coupled to each of the plurality of optical fibers for grounding each short-haul utility conveyance in response to the optical signal on a corresponding optical fiber.

Abstract: A cable detection apparatus is disclosed having a filter, the filter transmitting components of a signal detected substantially at certain harmonics of a first frequency. The filter may also attenuate the signal at certain even harmonics thereof. A method of detecting and/or locating cables in the same manner is also disclosed.

Abstract: A sonde includes an elongate flexible ferromagnetic core and a coil surrounds an intermediate segment of the core. A housing surrounds and supports the coil. An electronic drive circuit is mounted in the housing for supplying the coil with an electric signal that will induce the core to emit electromagnetic signals at a predetermined strength and frequency that can be remotely detected. Self-contained battery powered float-type and pill-type sondes are also disclosed.

Abstract: A hand-held power tool is provided with a housing, an attachment member, and an object sensor that is removable from the attachment member. The attachment member may be removable from the tool. The object sensor, which can be used to detect studs hidden behind walls, electrical lines, and other materials, is readily accessible to tradesmen.

Abstract: In order to provide a triggering signal for a cable stripping device that is also capable of dealing with very thin wires, it is suggested to use a piezoelectric sensor, the output signal from which is forwarded to an electronic evaluation unit. The electronic evaluation unit then outputs a digital signal that enables the stripping process to be started safely. Various mechanical mechanisms are suggested to ensure that the digital signal is not triggered when not being touched. This problem is proposed to be solved by a low pass filter discriminating between sensor inputs by touching and vibration shock events, etc.

Abstract: An embodiment of the invention provides a sensing device that includes a sensing circuit and a mode selection input device. The sensing circuit senses the presence of an object beneath a surface. The mode selection input device allows a user to select, using a single button, a desired mode from among at least three sensitivity modes without first accessing another sensitivity mode. In another embodiment, a sensing device includes a sensing circuit and a display. The sensing circuit senses the presence of a live electrical wire beneath a surface. The display includes an optical element and a light source to indicate the sensed presence of the live electrical wire.

Abstract: A dynamic magnetic locator includes a linking mechanism linked with a first sensor to horizontal move or rotate the first sensor; a second sensor horizontally arranged beside the first sensor; a third sensor vertically arranged atop the second sensor; and a control module connected to the sensors and receiving magnetic signals of the underground metal pipe. The control module controls the linking mechanism to horizontal move or to rotate the first sensor to obtain a plurality of magnetic signals. The control module processes the magnetic signals to obtain a position and a depth of an underground metal pipe.

Abstract: A locator and marking apparatus comprises a housing and a surface on the housing for holding a magnet to be dispensed. Spacer members are formed on the housing such that the surface for holding the magnet is maintained a substantially predetermined distance from a substrate on which the locating and marking apparatus is positioned.

Abstract: Discriminating between a cable locating signal and a false cable locating signal is described. A reference signal, which contains a locating signal frequency impressed on it, is transmitted in a way which provides for detection of a phase shift between the locating signal and the false locating signal. Based on the phase shift, a receiver is used to distinguish the locating signal from the false locating signal.

Abstract: A hand-held power tool having a housing and a removably attachable portion. The removably attachable portion, which comprises an object sensor to detect studs hidden behind walls, electrical lines, and other materials, is readily accessible to tradesmen. A level may also be included on the removably attachable portion.

Abstract: A stud or joist sensor and associated sensing method using an amplitude and a ratio of capacitance measurements from a plurality of capacitive sensing elements. The sensor locates a feature of an object or discontinuity behind a surface or wall, such as an edge and/or a center of a stud behind the surface, a joist under a floorboard, a gap behind sheetrock, a metal conductor behind a surface or the like. The sensor may be moved over the surface, thereby detecting changes in capacitance. The change in capacitance is due to the effective dielectric constant caused by the passage over a hidden object such as a stud. When two capacitive sensing elements provide equivalent capacitance measures, the sensor is over a centerline of the stud. When a ratio of the capacitance measurements equals a transition ratio, the sensor is over an edge of the stud. When the sensor is over the stud and the capacitance measurements are low, the sensor is over a deep stud.

Abstract: An electrical conductor locating device comprises a pulse generator and a detector. The pulse generator includes a transformer with outputs for connecting to two positions along the electrical conductor to define a closed loop. The current in the closed loop produces an electromagnetic field around the conductor. The detector is comprised of a magnetic field sensor coupled to the input of an amplifier. The output of the amplifier is connected to an indicator, such as a LED. When the sensor is moved perpendicularly closer to the conductor, it senses an increasing magnetic or electromagnetic field strength so the amplifier drives the indicator at greater intensity. When the sensor is directly aligned with the conductor, the sensor is inside the equipotential point of the magnetic or electromagnetic field where the field strength approaches zero, so the amplifier drives the indicator at close to zero intensity and thus pinpoints the conductor.

Abstract: The invention relates to a transmitter loop configuration used for ground and downhole electromagnetic geophysical surveys. The loop wire is spread out on the ground surface in such a way as to form several subset loops in series. Each subset loop can be juxtaposed to each other or separated by a fixed distance. The contribution of each subset to the primary electromagnetic field is improved in intensity and vector orientation so as to energize more efficiently buried geological conductors. This design generates a strong sub-horizontal primary field in an in-loop zone of the global loop. Any sub-vertical conductor buried under this in-loop zone will be maximum-coupled and will generate a secondary electromagnetic field detectable by a receiver device. This invention includes the possibility of using a combination a several pairs of loops.

Abstract: A stud or joist sensor device and associated sensing method using a ratio of capacitance measurements from a plurality of capacitive sensing elements. The device locates a feature of an object or discontinuity behind a surface or wall, such as an edge and/or a center of a stud behind the surface, a joist under a floorboard, a gap behind sheetrock, a metal conductor behind a surface or the like. The device may be moved over a surface, thereby detecting changes in capacitance. The change in capacitance is due to the effective dielectric constant caused by the passage over an object such as a stud. When two capacitive sensing elements provide equivalent capacitance measures, the device is over a centerline of the stud. When a ratio of the capacitance measurements equals a transition ratio, the device is over an edge of the stud.

Abstract: A method for locating objects enclosed in a medium, according to which a detection signal is generated by at least one capacitive sensor device, the detection signal penetrating the medium that is to be analyzed in such a way that information is obtained about an object that is enclosed in the medium by evaluating the detection signal, particularly by measuring impedance, wherein, to obtain depth information about the object that is enclosed in the medium, an algorithm is used to evaluate the detection signal that calculates a compensation for drift effects of the capacitive sensor device that is generating the detection signal.

Abstract: In a method of identifying a passive electromagnetic signal emitted from an underground utility, a portable above-ground antenna is disposed at a location at which the passive electromagnetic signal is expected. Measurement signals are received from the antenna corresponding to electromagnetic signals received by the antenna. The measurement signals are measured at a plurality of different frequency bands within a measurement frequency range expected to include a frequency of the passive electromagnetic signal, and at least one of the plurality of frequency bands is selected based on a predetermined criteria applied to the measurements.

Abstract: The apparatus can continuously determine the location at which a cable is buried. Location data of a measurement standard position is acquired by RTK-GPS. The azimuth of the moving direction of the apparatus is calculated using the location data. Electromagnetic waves from a metallic wire are received by two electromagnetic signal receiving sections whose locations in the horizontal plane are different from each other, and distances from the measurement standard position to a cable in a measurement base line direction and in the vertical downward direction are calculated using the received electromagnetic signals. The depth of the cable is calculated using the distance in the vertical downward direction. The plane location data of the cable is calculated using the azimuth of the moving direction, the location data of the measurement standard position, and the distance in the measurement base line direction.

Abstract: A surface tracker includes a tubular marker body having an interior electronic marker and a visual indicator attached to an upper end of the marker body which extends away from the marker body. When deployed, the marker body is mostly underground and the visual indictor extends upwardly from the ground level to provide above-ground visual recognition. The visual indicator may be a plurality of resilient filaments which pass through a hole in a tab portion of the marker body at the upper end thereof, the filaments being folded about the tab portion and secured to the tab portion using a heat-shrink tube. The visual indication, along with the ability to electronically detect the marker, provides a tracker with superior locating capability.

Abstract: A boring tool is moved through the ground in a region which includes at least one electrically conductive in-ground line and which is subject to static magnetic fields including the magnetic field of the earth.

Abstract: When cables run side by side over a longer distance, an alternating-current signal used for cable location can couple or ‘bleedover’ to neighboring cables. The coupled current flowing in the neighboring cable creates field distortion and makes position determination of the targeted cable difficult. The resulting magnetic field of both (or more) cables has a non-circular shape and is commonly known as a distorted field. Established methods for finding the position of the cable under investigation lead to inaccuracies or even wrong locates. The method described herein eliminates the field distortion that is due to the coupled cables by demodulating a phase reference signal placed on the cable by a transmitter into two signal strength constituents. The inphase signal represents the field strength of the targeted conductor and is substantially free of field distortion. The other quadrature signal contains the component of the field associated with distortion.

Abstract: A method for locating objects enclosed in a medium, according to which a detection signal is generated by at least one capacitive sensor device, the detection signal penetrating the medium that is to be analyzed in such a way that information is obtained about the objects that are enclosed in the medium by evaluating the detection signal, particularly by measuring impedance, wherein, in order to obtain information about the depth of an object that is enclosed in the medium, a phase measurement of a variable which is correlated with a shift current of the capacitive sensor device is utilized.

Abstract: An apparatus for locating a buried utility conveyance, such as an undersea cable, beneath a body of water. The apparatus generally comprises a submersible housing that contains a variable ballast system for selectively controlling the buoyancy of the apparatus, operator-controlled maneuvering apparatus, and a detector assembly for locating the conveyance. The detector assembly includes first and second signal generators and first and second signal detectors for vectoring the location of the conveyance. An operator guides the detector relative to a target search location through cables attached to the housing and the variable ballast system. A camera generates images of the target search location for use by the operator to control the apparatus through an umbilical cable connected to the housing.

Abstract: A stud finder for a light generating device, having a surface and a connection structure on the surface to removably mount either a light generating device or a leveling device thereto.

Abstract: A constant current termination is provided for cable locating tones on communication and control cables that may be buried or placed in underground duct structures. The constant current termination limits the current on each branch of the cable to that required for cable location, thus ensuring that branches furthest from the tone source have adequate current for location purposes. The termination is the same for each branch, regardless of its position along the cable system. This eliminates the need to calibrate and recalibrate termination distances for a cable on installation and when branches are added. It also allows the location of damaged cables where the tone signal strength on a damaged branch is less than that for which the termination was designed.

Abstract: The present invention is a technique for locating and identifying a failed filter/arrester in an underground conveyance such as a fiber optic cable. A sensor is installed in the filter/arrester housing to sense grounding of a cable locating frequency. The sensor will monitor the cable locating signal that is normally on the cable and blocked by the filter arrester to ground. A small radio frequency oscillator (85 to 88 Hz), also installed inside the filter housing, is activated by the sensor. The RF signal is detected above ground with standard cable locating equipment. A warning indicator such as an indicator light may also be installed on the outside of the filter housing. The indicator is also activated by the sensor. In that way, the particular failed filter can be identified if multiple filters are installed at that location. The power that will be required to operate the RF transmitter and indicator will be obtained from the voltage passing through the cable.

Abstract: A sensor and method that detects a mis-calibration and automatically recalibrates itself without operator intervention. If the sensor determines that it was calibrated over an object such as a stud, the sensor may automatically update the calibration value with a new lower value without operator intervention. This process may repeat until the calibration value is set to a value that represents the wall covering alone without hidden objects behind it.

Abstract: A portable locator and method for establishing the location of the cable line in a region which includes at least one generally straight electrically conductive cable line extending across the region from which cable line a locating signal includes a first arrangement for measuring a local flux intensity of the locating signal at a first above ground point within the region with the portable locator in a particular orientation at the first above ground point. A second arrangement uses the local flux intensity to establish a cable line angular orientation which limits the possible directions to the cable line relative to the particular orientation of the portable locator at the above ground point. A third arrangement uses the measured local flux intensity to establish an actual direction of the cable line that is selected from the possible directions based on certain characteristics of the locating signal.

Abstract: A method and apparatus includes a signal generator, a power supply, a micro-controller a transmitter and a receiver for determining the condition of a line. The signal is passed through the line and any reflection is used to determine varying characteristics of the line.

Abstract: A transmitter that is electrically connected to a circuit and an associated receiver is used to identify an element of that circuit in the presence of other circuits. This may be used in AC or DC systems that are powered or not to identify or trace circuit elements such as lines, junctions, switches, fuses, or breakers. One version that identifies the circuit breaker of the circuit connected to the transmitter in a powered AC distribution system.

Abstract: A method for locating a device producing a magnetic field in a blind or inaccessible position of a work piece. A magnet is initially placed on a first side of the work piece such that a magnetic field produced by the magnet extends through the work piece. Probes are then positioned over a second surface of the work piece to determine the location of the axis of the magnet via the strength of the sensed magnetic field and the location where the strength measurements are made. Once the position of the axis of the magnet is determined, the work surface is either marked or worked on through the platform on which the probes are positioned. In particular, the present invention allows a very accurate positioning of a work tool on the second surface without the need to first visualize the first surface of the work piece.

Abstract: A transmission line protection system comprising at least one signal carrying line buried adjacent the transmission line to be protected, means transmitting a signal through said signal carrying line, and means responsive to damage or severance of said signal carrying line to indicate that said signal carrying line has been damaged or severed and the location of the damage or severance.

Abstract: A device for locating an object behind a wall lining includes a housing having a front portion fitting substantially in the palm of a user's hand. Operating switches are located in juxtaposition to the grip portion so as to be operable by the user without substantially altering grip on the housing. The device also includes a sensor including a first capacitor plate and a pair of second capacitor plates. The capacitor plates are arranged serially, and calibrated by a pulse width modulator and integrator. Operating electronics are incorporated into an application specific integrated circuit.

Abstract: The invention relates to a locator, in particular a handheld locator for detecting inclusions in walls, ceilings and/or floors, having a capacitive sensor device disposed in a housing, having means for generating a detection sensor of the at least one capacitive sensor device, having a control and evaluation unit, communicating with the sensor device, for ascertaining measurement values from the detection sensor, and having an output unit for reproducing measurement values of the capacitive sensor device. According to the invention, it is proposed that a measuring capacitor (16) of the capacitive sensor device (10) has a first electrode (21), which includes one face of the housing (14) of the sensor device (10).

Abstract: A boring tool is moved through the ground in a region which includes at least one electrically conductive in-ground line and which is subject to static magnetic fields including tie magnetic field of the earth.

Abstract: An apparatus for locating a buried utility conveyance, such as an undersea cable, beneath a body of water. The apparatus generally comprises a submersible housing that contains a variable ballast system for selectively controlling the buoyancy of the apparatus, and a detector assembly for locating the conveyance. The detector assembly includes first and second signal generators and first and second signal detectors vectoring the location of the conveyance. An operator guides the detector relative to a target search location through cables attached to the housing and the variable ballast system. A camera generates images of the target search location for use by the operator to control the apparatus through an umbilical cable connected to the housing.

Abstract: A pocket-sized object finder has a compact housing containing a battery, circuitry and a capacitor plate for detecting an object hidden behind a wall. The battery powered circuitry includes multiple signal indicators that illuminate in a serial manner when the object is being detected. The signal indicators are successively tapered and are mounted at a front side of a tapered end of the housing. The capacitor plate is disposed in the housing along its rear wall and is responsive to variations in capacitance that occur as the object finder is brought near and over the object. The compact housing defines a cavity with a width that is no more than two inches and one third its length. A removable access door, with a pocket clip, at an end opposite the signal indicators allows access to the battery within the housing cavity.

Abstract: A system for locating a circuit interrupter associated with a selected branch circuit. The system includes a passive transmitter that creates a current spike at a predetermined frequency and a receiver broadly tuned about that predetermined frequency. The current spike signal has a sufficiently short spike duration and a sufficient amplitude so as to substantially minimize development of a sympathetic signal on other branch circuits adjacent to the selected branch circuit. The passive transmitter includes a voltage controlled switch in series with a charge storage device. The receiver drives a user-perceivable signaling device upon sensing the current spike. Related subsystems and methods are also disclosed.

Abstract: Apparatus for dispensing paper from rolls which feeds continuously, roll to roll, and does not require extra procedure to bring stub roll into position. The apparatus holds and positions at least first and second rolls of paper with respect to each other; dispenses paper from the first roll; dispenses paper from the first and second rolls simultaneously when the first roll reduces to a predetermined diameter of paper, positions the depleted first roll for replacement without the necessity of removing the second roll; and dispenses from the second and replacement rolls simultaneously when the second roll reduces to a predetermined diameter of paper. The apparatus also has a proximity sensor, which senses when a hand is placed near the dispenser, and thereupon dispenses a set amount of towel. The proximity sensor incorporates “static” and noise immunity circuitry.

Abstract: The invention relates to a method for locating objects enclosed in a medium, according to which a detection signal is generated by at least one capacitive sensor device. Said detection signal penetrates the medium that is to be analyzed in such a way that information is obtained about objects enclosed in the medium by evaluating the detection signal, particularly by measuring impedance.

Abstract: An inductive sensor arrangement for detecting ferromagnetic or non-ferrous electrically conducting objects hidden in a surrounding medium comprising three field coils arranged in essentially the same geometric plane and adjacently positioned at angular distances of usually 120° from each other around a central axis orthogonal to the plane for generating an alternating magnetic flux by a sequential excitation with an AC-current ramp. The sensor arrangement further comprises three sense coils respectively mounted inside each associated field coil and in an orientation to the axes of each of the field coils such that essentially no voltage is induced in the sensor coils in an environment free of a metallic object.

Abstract: In a method of identifying a passive electromagnetic signal emitted from an underground utility, a portable above-ground antenna is disposed at a location at which the passive electromagnetic signal is expected. Measurement signals are received from the antenna corresponding to electromagnetic signals received by the antenna. The measurement signals are measured at a plurality of different frequency bands within a measurement frequency range expected to include a frequency of the passive electromagnetic signal, and at least one of the plurality of frequency bands is selected based on a predetermined criteria applied to the measurements.

Abstract: A body detecting element is buried in the ground together with a body such as a metal body and includes a magnetic member acting as a magnetic core, an antenna coil wound around the magnetic member and a capacitor connected to both the ends of the antenna coil for forming a resonance circuit together with the antenna coil. The antenna coil is mounted on the body integrally therewith through an electromagnetic shield member with the outer peripheral surface thereof confronting the outer surface of the body. A body detecting element includes an RFID circuit connected to the antenna coil and mounted on a body integrally therewith such that the outer peripheral surface of the antenna coil confronts the outer surface of the body through an electromagnetic shield member. Even if the body detecting element is mounted on the body such as the metal pipe integrally therewith, it can accurately detect the body because a resonant frequency and the Q value of the coil are not changed.

Abstract: The invention relates to a method for locating objects enclosed in a medium, according to which a detection signal is generated by at least one capacitive sensor device. Said detection signal penetrates the medium that is to be analyzed in such a way that information is obtained about the objects that are enclosed in the medium by evaluating the detection signal, particularly by measuring impedance.

Abstract: A metal detector having a plurality of phase delay discrimination regions with corresponding selectable exception spaces therein.

Abstract: A metal detector that includes a substantially non-metallic housing that defines a hollow cavity and a human walking surface and a metal scanner element positioned in the hollow cavity defined by the non-metallic housing, wherein the walking surface receives a covered human foot. This invention allows travelers to leave their shoes on while transiting security checkpoints.