A crack sensor for detecting the extension of a crack comprises an insulator base material made from an insulating material, a common line formed on the insulator base material along a first direction and a plurality of gauge lead wires which is formed on the insulator base material and each of which has an end connected with the common line at an interval and another end extending in a second direction orthogonal to the first direction, wherein the extending end reaches a position to which the extending end retreats in a direction opposite to the first direction with respect to the end connected with the common line.

A system includes a substrate having a surface and a circuit with a plurality of conductive paths disposed adjacent (e.g., directly on or separated by a thin layer). The circuit is configured to detect an interruption or alteration of conduction of one or more of the plurality of conductive paths due to a flaw in the substrate. The circuit is further configured to identify the interrupted or altered one or more of the plurality of conductive paths based on one or more electrical characteristics of the circuit.

This disclosure provides a method and device for detecting the damage rate of an inner coating of a downhole oil casing. The method includes filling the oil casing with electrolyte, obtaining the well depth-detection current on a discharge electrode in a process of moving the discharge electrode from one end of the oil casing to the other end of the oil casing, and determining a well depth-damage rate state of the inner coating of the oil casing according to the well depth-detection current. This application can realize quantitative judgment for the damage rate of an inner coating of a downhole oil casing, resulting in rapid in detection speed, convenient and safe in operation, and low detection cost.

A method of producing a spark plug comprises (a) a step of combining a metallic shell and an insulator; (b) a step of inserting a portion of the assembly on its forward end side into a pressure container; (c) a step of bringing an insulating member into contact with the outer circumferential surface of a base side portion of the insulator over the entire circumference thereof, and pressing the assembly so as to close the opening by the assembly; and (d) a step of pressurizing the interior of the pressure container and applying a predetermined voltage between the terminal electrode and the metallic shell, wherein the step (b) includes a step of inserting the portion of the assembly on the forward end side into the pressure container such that a gap formed between the outer surface of the insulator and the inner surface of the metallic shell on the forward end side of the assembly is disposed in the pressure container.

Some embodiments include a sensor assembly comprising a sensor to be carried by a movable component movably positionable about a tool body of a downhole tool. The sensor is to take wellsite measurements and the downhole tool is positionable in a wellbore. The sensor assembly further includes electronics positionable in the movable component. The electronics are to electrically connect to the sensor to receive the wellsite measurements from the sensor, and the wellsite measurements are usable to determine wellsite parameters.

Tamper-respondent assemblies and methods of fabrication are provided which include at least one tamper-respondent sensor and a detector. The at least one tamper-respondent sensor includes conductive lines which form, at least in part, at least one tamper-detect network of the tamper-respondent sensor(s). The detector monitors the tamper-respondent sensor(s) by applying an electrical signal to the conductive lines of the at least one tamper-respondent sensor to monitor over time for a non-linear conductivity change indicative of a tamper event at the tamper-respondent sensor(s). For instance, the detector may monitor a second harmonic of the electrical signal applied to the conductive lines for the non-linear conductivity change indicative of the tamper event, such as an attempted shunt of one or more conductive lines of the tamper-respondent sensor(s).

An inspection apparatus for testing of objects synchronizes a spark test wheel having probe fingers with a transportation unit on which spaced objects to be spark tested are placed. The probe fingers are arranged conically when the transportation unit is a turret.

Provided is a method for inspecting a heat sink that enables an accurate inspection of an insulating film formed on a surface of heat sink fins. The method including a metallic housing that includes a plurality of cooling fins arranged side by side on an outer surface thereof, and an insulating film formed on a surface of the cooling fins and between the cooling fins. The method includes disposing, in an electrolyte solution, an inspection electrode including a plurality of electrode fins insertable between the cooling fins to face the housing with a predetermined distance therebetween in such a way that the cooling fins and the electrode fins are alternately arranged; and applying a voltage between the housing and the inspection electrode, which are arranged to face each other, and inspecting a formation state of the insulating film based on a measured value of a current.

A sensor assembly for a downhole tool including a tool body and a movable component movably positionable about the tool body is disclosed. The sensor assembly may include a wear sensor and/or a position sensor. The wear sensor may include a core with conductors at various depths to send a signal, whereby, upon wear of the core, a change in the signal at the depth of the wear is detectable. The position sensor may be carried by the movable component, and may be used with references comprising magnets distributed about the tool body. The position sensor includes magnets having polarity responsive to polarity of the references whereby a position of the movable component is determined. The sensor assembly may also include a chassis housing electronics coupled to the position sensor and/or the wear sensor.

An apparatus to enamel rate a selected region of a metal object, such as the rivet area of a lid 40 of a food or beverage container by the adaption of a lid of an electrolyte vessel to direct electrolyte specifically to an area T that requires testing, with the rest of the object being kept dry and separate from the area to be tested. The vessel plate has a main body 16 configured as a lid for attachment to a test chamber and an adapter 20 configured to receive the metal object therein, the adapter having a base 21 and a perimeter wall 23 extending outwardly from the plate, the perimeter wall having a seal 22 mounted thereon, the base of the adapter having at least one aperture 28 surrounded by a secondary seal 24.