Abstract: A system and method for locating flaws in cable shields and electromagnetic tubing (shield conduit) without disconnection of the cable or conduit under test is described. The fault location method, using a unique sensor array and fault detection circuit, supplements capabilities of earlier inductance/resistance tester. Previous inductance/resistance testers allow the user to measure very small resistances at cable/connector joints, usually without disconnecting the circuit under test.

Abstract: An armed-state detector for the testing of "live" antitank mines is discld. The invention allows a user to determine, from a safe distance, if a mine is in an "active" state. A pole mounted sensor array is placed over the mine to sample the weak repetitive magnetic field that emanates from "active" mines. A hand-held, battery powered, detector box provides an audible or visual indication of whether or not the mine is "active". In addition to indicating that the mine is "active", the armed-state detector allows the user to determine the angular orientation of the magnetometer common to all antitank mines. The detector also provides a means whereby limited diagnostics can be performed on an unexploded mine. With the armed-state detector the user can determine if the fuze of an unexploded mine has been "killed" outright, or has merely failed to respond to the test stimulus.

Abstract: A buried pipe detection device based upon the principle of sensing of difences in the dielectric/conductive properties of the ground in the vicinity of the pipe is disclosed. Because the electrical properties of the ground directly over the buried pipe will differ from those of an area immediately adjacent to the pipe, the detection principle is embodied in a capacitor plate array that injects a low frequency sinusoidal signal into the ground and samples the injected signal from two spatially separated locations on the array. The capacitor plate array has two injector/sensor plates that form a capacitively coupled impedance bridge with the ground and a third plate to establish circuit ground. The injector/sensor plates sense changes in the ground path impedance directly beneath the plates as the array is moved along the ground. The outputs of the two sensor/injector plates are then combined differentially and are processed to provide a continuous analog or digital readout.

Abstract: A technique and apparatus for measurement of resistances of 0.025 ohm and ss without disconnection from the circuit. The invention is used for measurement of degradation in cable shields. The method can also be used for measurement of junction resistances in high current circuits such as auto starters. The invention allows measurements to be made with the circuits connected so that the faults are present in the measurement setup. The method includes inductive coupling of long duration repetitive current pulses onto the circuit under test, measurement and display of induced current and voltage pulses, and display of induced current and voltage pulses on an oscilloscope.

Abstract: A technique and apparatus for measurement of resistances of 0.01 ohm and s without disconnection from the circuit. The invention is used for measurement of degradation in cable shields by measuring the droop caused by circuit resistance in an induced current pulse in the undisconnected circuit. The method can also be used for measurement of junction resistances in high current circuits such as auto starters. The invention allows measurements to be made with the circuits connected so that the faults are present in the measurement setup. The method includes inductive coupling of long duration repetitive current pulses onto the circuit under test, measurement and display of induced current pulses, and display of induced current pulses on an oscilloscope.

Abstract: A Surge Protection Device Test Fixture having a metallic housing with a bs coverplate, the housing having an input coaxial connector and an output coaxial connector mounted on either end, a bare wire conductor connecting the center conductor of the input coaxial connector to the center conductor of the output coaxial connector, a teflon holder located within the housing for holding a surge protection device and positioned so as to allow the surge protection device to make contact with the bare wire conductor, an adjustable contact screw for providing a conducting path between the brass coverplate and the surge protection device, a coil for inductively sensing a current through the surge protection device, a coil for inductively sensing a current through the bare wire conductor, and a coil for inductively sensing a current on the outside of the housing.

Abstract: A dual purpose probe for the simultaneous sampling of the voltage and curt at a test point. The device includes a capacitive probe for measuring voltage, and a small solenoid type inductor for measuring current when affixed so that it is at right angles to the wire being sampled. A small, double-sided circuit board has the inductor mounted thereon as well as a small metallic pick up plate which serves as one plate of a capacitor when the probe is affixed in the measuring position, while the conductor being sampled forms the other plate of the capacitor, and the insulation around the conductor serves as the capacitor dielectric.

Abstract: A method and device for testing transient protection circuits comprising itive and negative high voltage protection circuits and high voltage fast rise time protection circuits. A bipolar test signal with alternate positive and negative high voltage pulses is applied to the circuit under test. Determination is made whether the pulses are within a predetermined voltage window. Signals indicating pass/fail responsive to that determination are generated. A high voltage fast rise time negative pulse is applied to the circuit under test. Changes in the voltage-time waveform are sensed and compared to predetermined levels. Pass/fail signals are generated in response to the comparison.

Abstract: An apparatus for detecting mechanical vibration in the presence of an electromagnetic pulse, which is of particular use in the testing of land mines. An optical fiber link is provided between the device under test and a remote data collection station. A vibration sensor and optical transmitter are secured to the device under test, while an optical receiver and event latch are present at the other end of the fiber link at the data collection station.