Abstract: Some embodiments concern a method of detecting usage of one or more electrical devices coupled to an electrical power line. An electrical power signal with a predetermined period is on the electrical power line. The one or more electrical devices place one or more noise signals on the electrical power line. The electrical power signal comprises the one or more noise signals. The method can include: using a data acquisition device to acquire first data about the electrical power signal on the electrical power line such that the acquiring of the first data is synchronized with the predetermined period of the electrical power signal; processing the first data to create frequency domain data; and applying a feature extraction algorithm to the frequency domain data to determine a transition of an electrical state of at least a first one of the one or more electrical devices. Other embodiments are disclosed.

Abstract: A stress detecting system and method operable to detect stresses in a conduit or pipe includes a tool movable along a conduit or pipe and operable to generate a magnetic field. The tool is operable to sense magnetic Barkhausen noise within the conduit, such as within a wall of the conduit, in response to the tool generating the magnetic field. The stress detecting system is operable to detect a change in stress along the conduit responsive to an output of the tool. The system may detect changes in stress that are caused by geological changes or shifting or thermal changes at or near the conduit to determine changes in stress along the conduit and changes in stress along the conduit over time and during use of the conduit.

Abstract: Some embodiments concern a method of detecting usage of one or more electrical devices coupled to an electrical power line. An electrical power signal with a predetermined period is on the electrical power line. The one or more electrical devices place one or more noise signals on the electrical power line. The electrical power signal comprises the one or more noise signals. The method can include: using a data acquisition device to acquire first data about the electrical power signal on the electrical power line such that the acquiring of the first data is synchronized with the predetermined period of the electrical power signal; processing the first data to create frequency domain data; and applying a feature extraction algorithm to the frequency domain data to determine a transition of an electrical state of at least a first one of the one or more electrical devices. Other embodiments are disclosed.

Abstract: A tool disposable within a well pipe, such as for detecting a freepoint of a well pipe, includes an electromagnet capable of inducing a magnetic field within a wall of a well pipe. The tool includes a Barkhausen noise sensing device capable of sensing magnetic Barkhausen noise in response to the electromagnet inducing the magnetic field within the wall of the well pipe. The tool may be moved along the well pipe so as make two passes of the tool along the well pipe, with one pass being performed while the well pipe is less stressed and the other pass being performed while the well pipe is more stressed, with the output of the tool during a first pass being compared to the output of the tool during a second pass to determine the location of the freepoint of the well pipe.