A measurement device and measurement method for evaluating an acoustic device that allows a sound to be transmitted via vibration transmission by being held by a human ear includes an ear model unit having an ear model modeled after a human ear and an artificial external ear canal unit continuous with the ear model. The ear model unit is formed from rubber, a same material as an auricle model conforming to IEC 60318-7 or IEC 60268-7, or a material having a Shore hardness of from 30 to 60. The ear model is provided with an auricle or a hole which holds the acoustic device. A microphone is configured to measure an air-conducted component generated within an artificial ear canal of the artificial ear canal unit by vibration transmitted to the ear model unit from the acoustic device held by the auricle or the hole.

A measurement device and measurement method for evaluating an acoustic device that allows a sound to be transmitted via vibration transmission by being held by a human ear includes an ear model unit having an ear model modeled after a human ear and an artificial external ear canal unit continuous with the ear model. The ear model unit is formed from rubber, a same material as an auricle model conforming to IEC 60318-7 or IEC 60268-7, or a material having a Shore hardness of from 30 to 60. The ear model is provided with an auricle or a hole which holds the acoustic device. A microphone is configured to measure an air-conducted component generated within an artificial ear canal of the artificial ear canal unit by vibration transmitted to the ear model unit from the acoustic device held by the auricle or the hole.

Disclosed are tools, systems, and methods for detecting one or more underground acoustic sources and localizing them in depth and radial distance from a wellbore, for example, for the purpose of finding underground fluid flows, such as may result from leaks in the well barriers. In various embodiments, acoustic-source detection and localization are accomplished with an array of at least three acoustic sensors disposed in the wellbore, in conjunction with array signal processing.

The present invention provides a sensor system for measuring a parameter (e.g. volume, temperature or pressure) of a target, the system comprising a diaphragm, a sensor for measuring the axial spacing between the sensor and the diaphragm, and an axially adjustable mount. The mount has a first axial end for mounting the diaphragm which is axially movable relative to the sensor and an opposing, second axial end which is axially fixed relative to the sensor. The diaphragm and mount define a chamber for receiving the target or for being received within the target. In use, the axial spacing between the first axial end and the second axial end of the mount and thus the axial spacing between the diaphragm and sensor varies as a result of a change in the parameter differential across the diaphragm.

The present invention provides a sensor system for measuring a parameter (e.g. volume, temperature or pressure) of a target, the system comprising a diaphragm, a sensor for measuring the axial spacing between the sensor and the diaphragm, and an axially adjustable mount. The mount has a first axial end for mounting the diaphragm which is axially movable relative to the sensor and an opposing, second axial end which is axially fixed relative to the sensor. The diaphragm and mount define a chamber for receiving the target or for being received within the target. In use, the axial spacing between the first axial end and the second axial end of the mount and thus the axial spacing between the diaphragm and sensor varies as a result of a change in the parameter differential across the diaphragm.

If a failure of components of a transport-system sliding contact can be predicted, preventive maintenance that is sometimes unnecessary is eliminated and an alternative run-to-failure approach associated with downtime can be avoided. A system and a method detect wear of a transport system, which system has a sliding contact with a current collector and a current-carrying conductor. A current-collector vibration sensor mounted on the current collector is configured to register vibrations produced by driving motion of the vehicle along the current-carrying conductor and to wirelessly transmit the vibrations to a background system. The background system is configured to subject data transmitted to the background system, in particular the registered vibrations, to an analysis and to signal wear of the transport system, in particular wear of the current collector and/or of the current-carrying conductor, on the basis of the analysis.

If a failure of components of a transport-system sliding contact can be predicted, preventive maintenance that is sometimes unnecessary is eliminated and an alternative run-to-failure approach associated with downtime can be avoided. A system and a method detect wear of a transport system, which system has a sliding contact with a current collector and a current-carrying conductor. A current-collector vibration sensor mounted on the current collector is configured to register vibrations produced by driving motion of the vehicle along the current-carrying conductor and to wirelessly transmit the vibrations to a background system. The background system is configured to subject data transmitted to the background system, in particular the registered vibrations, to an analysis and to signal wear of the transport system, in particular wear of the current collector and/or of the current-carrying conductor, on the basis of the analysis.

A looseness detection structure configured to detect looseness between a bolt and a nut that fix two components including a conductive film configured to be attached on a surface of the component, the surface of the component including a hole into which the bolt is inserted, the conductive film being attached such that the conductive film is not directly conductive to the component, a part of the conductive film having a dimension relating to a half wavelength of a high-frequency signal propagating inside the components, and a non-conductive film between a surface of the component and the conductive film in a case where surfaces of the components are conductors, and a second conductive film on a surface of the component in a case where the surfaces of the components are insulators, the second conductive film being opposite to the conductive film.

A looseness detection structure configured to detect looseness between a bolt and a nut that fix two components including a conductive film configured to be attached on a surface of the component, the surface of the component including a hole into which the bolt is inserted, the conductive film being attached such that the conductive film is not directly conductive to the component, a part of the conductive film having a dimension relating to a half wavelength of a high-frequency signal propagating inside the components, and a non-conductive film between a surface of the component and the conductive film in a case where surfaces of the components are conductors, and a second conductive film on a surface of the component in a case where the surfaces of the components are insulators, the second conductive film being opposite to the conductive film.

Disclosed are tools, systems, and methods for detecting one or more underground acoustic sources and localizing them in depth and radial distance from a wellbore, for example, for the purpose of finding underground fluid flows, such as may result from leaks in the well barriers. In various embodiments, acoustic-source detection and localization are accomplished with an array of at least three acoustic sensors disposed in the wellbore, in conjunction with array signal processing.