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 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).

Disclosed are several examples of a system and method for detecting if an article is being tampered with. Included is a covering made of a substrate that is coated with a layer of an electrically conductive material that forms an electrically conductive surface having an electrical resistance. The covering is configured to at least partially encapsulate the article such that the article cannot be tampered with, without modifying the electrical resistance of the electrically conductive surface of the covering. A sensing device is affixed to the electrically conductive surface of the covering and the sensing device monitors the condition of the covering by producing a signal that is indicative of the electrical resistance of the electrically conductive surface of the covering. A measured electrical resistance that differs from a nominal electrical resistance is indicative of a covering that is being tampered with and an alert is communicated to an observer.

A variety of methods, apparatuses, and systems are disclosed, involving, in one example, a method including traversing the length of a conductive substrate with a holiday detector, inducing an arc voltage at a defect of a coating disposed on the conductive substrate, detecting the arc voltage with sensors, and recording an electrode voltage with electronics disposed at the holiday detector.

An apparatus for measuring micro-cracks in a membrane electrode assembly includes a resistance measurement unit to measure variation in electrical resistance of the membrane electrode assembly while tensioning the membrane electrode assembly in a state in which power is applied to an upper catalyst layer while a lower catalyst layer is insulated, an image capture unit to capture an image of micro-cracks in the upper catalyst layer while the membrane electrode assembly is being tensioned, and a controller to detect, in real time, variation in electrical resistance measured by the resistance measurement unit, corresponding to the image of micro-cracks captured by the image capture unit, and to interpret the size of the micro-cracks generated in the membrane electrode assembly based on the detected variation in electrical resistance.

The present disclosure provides a battery inspection device and a battery inspection method. The battery inspection device includes: a plasma application unit irradiating plasma to a test object while being moved in a predetermined direction; a signal acquisition unit contacting the test object and electrically connected thereto, and receiving an electrical signal induced by plasma; and a control unit controlling the plasma application unit and the signal acquisition unit, wherein the control unit determines whether damage has occurred to the exterior of the test object by analyzing a waveform derived from the electrical signal received from the signal acquisition unit.

A coated structure with a monitoring system includes a base having a base surface, a coating system having one or more layers of cured coat providing protection against surface degradation and being joined to the base surface in a base interface and extending in a thickness direction to an outer coating surface, at least one electrode made from a conductive material embedded in the coating system. The monitoring system is configured to generate an input signal in the at least one electrode and to read an output signal from the at least one electrode, and from the output signal, to determine cracking of the one or more layers of cured coat.

A coated structure with a monitoring system includes a base having a base surface, a coating system having one or more layers of cured coat providing protection against surface degradation and being joined to the base surface in a base interface and extending in a thickness direction to an outer coating surface, at least one electrode made from a conductive material embedded in the coating system. The monitoring system is configured to generate an input signal in the at least one electrode and to read an output signal from the at least one electrode, and from the output signal, to determine cracking of the one or more layers of cured coat

Embodiments herein relate to systems and methods for varnish detection and/or monitoring in hydrocarbon fluids. In various embodiments, a system for monitoring varnish compounds in fluids is included herein including a control circuit in communication with a fluid property sensor. The system can measure one or more fluid properties (such as dielectric constant, density, resistivity, viscosity and the like) with the fluid property sensor, monitor the same over a time period, and identify an occurrence of a rate of change in the measured property indicating a presence of the varnish compounds. In various embodiments, a system herein can be configured to measure a fluid property of a fluid with a fluid property sensor, monitor the fluid property value over a time period, and predict a time of the onset of varnish compound formation based on the trend of the fluid property value over time. Other embodiments are also included herein.