A method for determining a location of a proppant in a subterranean formation includes obtaining a first set of data in a wellbore using a downhole tool. The proppant is pumped into the wellbore after the first set of data is obtained. The proppant is pumped while or after the subterranean formation is fractured. A second set of data is obtained in the wellbore using the downhole tool after the proppant is pumped into the wellbore. The first set of data and the second set of data include a gravitational field measurement. The first and second sets of data are compared, and in response to the comparison, the location of the proppant in the subterranean formation is determined.

An optical position-measuring device for determining the position of a first object relative to a second object movable relative to the first object along a measurement direction includes a scale with a measuring graduation connected to the first object and extending along the measurement direction. A scanner is connected to the second object and includes a fiber-optic array including optical fibers. The fiber-optic array is configured as a fiber-optic plate having an image-input face facing the scale and an image-output face facing the detector array. The fiber-optic array transmits a light pattern into a detection plane of the detector array. An interstitial medium is disposed between the image-output face of the fiber-optic plate and the detector array to ensure that an amount of deflection that the beams exiting the image-output face undergo on a path to the detector array is smaller than in a case without the interstitial medium.

The system with branched optical fibers provides diagnostics and measurement of static and/or dynamic parameters in structures and structural elements. The system includes a structural material or element having a branched optical fiber embedded therein. The branched optical fiber includes a primary optical fiber segment and at least one secondary optical fiber segment branching therefrom. One or more fiber Bragg grating sensors are arranged on, and are in optical communication with, the primary optical fiber segment and the at least one secondary optical fiber segment. A signal analyzer receives signals generated by the fiber Bragg grating sensors representative of a magnitude of the physical parameter of the structural element.

A system that provides detection, annunciation, mitigation, and alleviation of stress attacks by executing algorithms based on measurement of intensity of light. The system determines to execute algorithms to take programmed action based on potential effects of a detected stress attack. The system can be used, for example, to determine the position of potential attacks to conduits that transport electricity, oil, gas, foodstuffs, water, people, and materials.

Embodiments disclosed herein include a substrate support having a sensor assembly, and processing chamber having the same. In one embodiment, a substrate support has a puck. The puck has a workpiece support surface and a gas hole exiting the workpiece support surface. A sensor assembly is disposed in the gas hole and configured to detect a metric indicative of a deflection of a workpiece disposed on the workpiece support surface, wherein the sensor assembly is configured to provide the benefit of allowing gas to flow past the sensor assembly when positioned in the gas hole.

A measurement device has a sensor and includes a cylindrical housing, an optical fiber that is disposed along the long-side direction of the housing and that has one end disposed in the housing and the other end disposed outside the housing, a first substrate including a light receiving unit disposed on an extension of the one end in the housing, and a second substrate that is electrically connected to the first substrate via a flexible part having flexibility and is disposed at an acute angle or a right angle with respect to the first substrate.

A system comprises a housing, a light source, a light guide configured to guide a light from the light source. The light guide includes a plurality of detection target configured to provide optical effect on the light in accordance with a bend state of the light guide. A light detector is configured to detect the light emitted from the light guide and provide information of the detected light. A communication unit is configured to transmit wirelessly the information of the detected light. The communication unit is disposed in the housing.

A sensor for measuring pressure, temperature or both may be provided. The sensor may include a diaphragm that may respond to a change in temperature or pressure, a base connected to the diaphragm, a cavity, and an optical fiber that may conduct light reflected off of a surface of the diaphragm. The diaphragm and base may be sapphire elements. An interrogator may be provided for detecting a deflection of the diaphragm.

A system for measuring subterranean physical properties, in some embodiments, comprises a source of broadband light, an input optical fiber coupled to the source of broadband light, a wavelength division demultiplexer coupled to the input optical fiber, a plurality of detectors arranged in parallel and coupled to the demultiplexer, a wavelength division multiplexer coupled to the plurality of detectors, and an output optical fiber coupled to the multiplexer.

An optical sensor (100) comprises: a holding sleeve (11); a fixed ferrule (12) fixedly mounted in said holding sleeve (11); a movable ferrule (13) movably mounted in said holding sleeve (11), a predetermined distance existing between a first movable end of said movable ferrule (13) and a first fixed end of said fixed ferrule (12) in said holding sleeve (11); a reflection part (14) arranged at a second movable end of said movable ferrule (13) opposite to said first movable end, for reflecting light entering the movable ferrule (13); and an actuation part (15), said actuation part (15) being constructed to drive said movable ferrule (13) to move so that said first movable end moves towards said first fixed end. An optical sensor assembly and a monitoring device comprising the optical sensor (100), or another sensor (1012) can remotely detect a mechanical movement in a passive mode. A first reflector (14, 1016) is configured to provide a first reflected optical signal. The sensor (100, 1012) is connected to the first reflector and has a first position and a second position, the second position configured to attenuate the first reflected optical signal more than the first position. The sensor is configured to move between the first and second positions in response to a monitored parameter (1018).