An assembly includes an electrical conductor disposed within an elongate mineral insulated conductive sheath. The electrical conductor is electrically grounded to the conductive sheath. The assembly also includes a test conductor disposed within and electrically isolated from the sheath to provide an indication of the insulation resistance of the assembly.

The disclosure provides for apparatus, including coated parts, where a base material of the part is coated with a multilayer coating. The multilayer coating includes at least three layers, including at least two electrically conductive layers. Also provided is a method for making apparatus, which includes providing a part and applying a multilayer coating to the base material of the part. Further provided is a method of monitoring and diagnosing a condition of a coated part. The method includes providing a coated part having a multilayer coating on a base material, measuring an electrical response of the multilayer coating, and correlating the electrical response with a condition of the multilayer coating.

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 plurality of assemblies are prepared, and a predetermined voltage is applied to a center electrode of each of the plurality of assemblies. The voltage applied to each of the plurality of center electrodes is detected by respective voltage sensors, and a differentiated value is calculated by differentiating the applied voltage, detected by each voltage sensor, with respect to time. A judgment is made as to whether or not a differentiated value change state in which an absolute value of the differentiated value becomes equal to or greater than a predetermined threshold value occurs. A judgment is made as to whether or not the occurrence of the differentiated value change state is caused by the noise, according to the voltage applied, for a specific time from the occurrence of the differentiated value change state, to the center electrode where the differentiated value change state has occurred.

A joint evaluation method of evaluating a joint state of a joint portion in a composite including the joint portion in which a first adherend and a second adherend are joined to each other through an adhesive is provided. The joint evaluation method includes applying an alternating-current signal to the joint portion; changing frequency to measure current and voltage; calculating an evaluation value related to a given electrical characteristic from a current value and a voltage value obtained by the measurement; comparing the evaluation value with a preset criterion related to the given electrical characteristic; and evaluating the joint state of the joint portion according to an amount of deviation of the evaluation value from the preset criterion.

A plurality of assemblies are prepared, and a predetermined voltage is applied to a center electrode of each of the plurality of assemblies. The voltage applied to each of the plurality of center electrodes is detected by respective voltage sensors, and a differentiated value is calculated by differentiating the applied voltage, detected by each voltage sensor, with respect to time. A judgment is made as to whether or not a differentiated value change state in which an absolute value of the differentiated value becomes equal to or greater than a predetermined threshold value occurs. A judgment is made as to whether or not the occurrence of the differentiated value change state is caused by the noise, according to the voltage applied, for a specific time from the occurrence of the differentiated value change state, to the center electrode where the differentiated value change state has occurred.

The present invention relates to damage detection systems for refractory linings for molten metal vessels, comprising an electrically conductive grid disposed underneath the surface of the refractory lining closest to a molten metal when in use, one or more electrically conductive electrodes disposed in contact with the molten metal when in use and an electrical power source, wherein the electrically conductive metallic grid and the one or more electrically conductive electrodes are electrically connected to each other, such as to form an open electrical circuit powered by the said electrical power source, and a detected closure of the said electrical circuit during normal use of the molten metal vessel indicates that the said refractory lining is damaged, or the presence of a molten metal during normal operation of the vessel closes the said electrical circuit in case the refractory lining is damaged. The present invention relates to a method for detecting damage in a refractory lining during use, and the use of a damage detection system according to the invention.

An integrated heated member management system includes: a cable module at least partially inserted into a heated member; a measurement module for measuring information generated in the cable module; an integrated management module for identifying a degree of damage to the heated member by a molten material on the basis of the information measured by the measurement module, to generate management information relating to the heated member; and a local terminal for receiving, from the integrated management module, the management information relating to the heated member.

An integrated heated member management system includes: a cable module at least partially inserted into a heated member; a measurement module for measuring information generated in the cable module; an integrated management module for identifying a degree of damage to the heated member by a molten material on the basis of the information measured by the measurement module, to generate management information relating to the heated member; and a local terminal for receiving, from the integrated management module, the management information relating to the heated member.

An assembly includes an electrical conductor disposed within an elongate mineral insulated conductive sheath. The electrical conductor is electrically grounded to the conductive sheath. The assembly also includes a test conductor disposed within and electrically isolated from the sheath to provide an indication of the insulation resistance of the assembly.