Inductive sensor

About: Inductive sensor is a research topic. Over the lifetime, 2282 publications have been published within this topic receiving 21984 citations.

Device for detecting electromagnetic stray effects in systems with at least two inductive sensors providing periodic output signal

Abstract: A device for detecting electromagnetic stray effects in systems with at least two inductive sensors which provide an essentially periodic output signal, performs a signal evaluation for evaluating signals of the sensors, a test for detecting an electromagnetic stray effect, whether periods of the signals to be evaluated lie within a period length of expected stray effects, a test, if applicable, whether detected signal progressions have at least a progression typical for stray pick-up, plausibility tests by means of at least one further detected signal in which a signal to be checked is compared with parallel measured other signals, and detecting a stray effect only if all tested conditions provide a result which is typical for stray effects.

A Stretchable Inductor With Integrated Strain Sensing and Wireless Signal Transfer

Abstract: Objective: A soft and stretchable inductive sensor is presented with the ability to wirelessly transmit large strain measurements without the need for directly connected circuitry. Methods: The sensor is fabricated using a scaffold-removal technique to create microfluidic channels within an elastomer sheet (0.07 MPa modulus), which are injected with a non-toxic liquid metal alloy electrode. An analytical model is derived to predict the static inductance of the sensor while being uniaxially stretched and experimental characterisation of the sensor’s dynamic response to axial and biaxial deformation is conducted, as well as wireless measurements within ex-vivo porcine tissue. Results: Experimental validation showed that the sensor’s inductance change is linear with uniaxial and biaxial strains up to twice its original length. Strain-rate dependent hysteresis was negligible during slow deformation ( $ ) and below 10% during more rapid changes in length ( $15\,\,{s}^{-{1}}$ ). For wireless strain sensing, the variation of inductance in the sensor induced an increase in the transmitting voltage from 3.1 V to 5.7 V for strains up to 83%. While implanted within different layers of porcine tissue, the transmitter voltage linearly increased by 750 mV on average under bending deformation. Conclusion: Large stretching (83%) and bending ( $8\,\,{m}^{-{1}}$ ) deformations in the inherently soft sensor can be wirelessly captured, including through biological tissue. Significance: The wireless sensor’s simplified structure, where the antenna and sensor are integrated into a single soft spiral electrode with modulus comparable to biological tissue, means that this novel design shows significant potential for implantable and wearable biomedical devices to monitor dynamic deformation.

Inductive and capacitive sensor arrays for in situ composition sensors

Abstract: Advances in electromagnetic sensor design provide the potential for high resolution imaging of subsurface objects and material properties at the microscopic (micrometer) and mesoscopic (meter) scales. With quasi-static, capacitive and inductive sensor arrays, objects are detected, identified, and imaged via their perturbations to the applied electric and magnetic fields, rather than through time delays of reflected electromagnetic waves as in ground penetrating radar. Building on the successful application as nondestructive quality assessment and monitoring tools as well as land mine detectors, several subsurface in situ sensors are enabled by this technology. Examples include: an electronic 3D microscope, enabling examination of cell level structures and composition; examination of near surface structures such as soil moisture, permafrost dynamics, soil properties with depth, root growth carbon sequestration, Martian surface aquifers, and buried deposits of carbon dioxide or methyl hydrides.

Power cable on-line diagnosis using partial discharges ultra wide band techniques

Abstract: A noninvasive ultra-wide band (UWB) partial discharge technique was employed in cable diagnosis of Mexico City underground distribution feeders. The technique presented here was applied to over 2000 joints, 400 terminals and thousands of meters of installed paper insulated impregnated cables rated at 23 kV. The technique allowed circuit classification according to electromagnetic field levels produced by partial discharges and recorded on each manhole with a joint along the circuits evaluated in 12 substations. The PD detection technique employs near field sensors working within the 80 MHz range and whose information is digitized and fed to a conventional PD digital detector, where a PD pattern is obtained. This pattern is correlated to the phase current by using an inductive sensor; therefore corona and interference problems could be disregard during measurements. To attain repetitive values, calibration was performed using a very fast pulse (less than 50 ns front) injected in a small cable loop. Results demonstrate a great signal to noise ratio, high selectivity and great noise discrimination. The large amount of measurements allowed the determination of limit values to differentiate areas in acceptable state from those requiring attention. Those results include detection of bad joints, cable deformation due to ducts collapse and damaged terminals, besides aged cable detection caused by overheating operation conditions. The results obtained had been confirmed by subsequent faults following the detection of very high levels of PD.

Sensor and sensing method

Abstract: A sensor is provided, which may include: a sensor layer containing a sensor material, wherein an electrical resistance of the sensor material changes upon adsorption of an adsorbate at the sensor material; a circuit electrically coupled to the sensor layer and configured to apply an electrical current to the sensor layer that heats the sensor layer.