Inductive sensor

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

Material condition assessment with spatially periodic field sensors

Abstract: Inductive sensors measure the near surface properties of conducting magnetic materials. The sensors generally include parallel winding segments to induce a spatially periodic magnetic field in a material under test. The sensors may provide a directionally dependent measure with measurements made in varying orientations of the sensor with respect to the material property variation directions. The sensors may be thin, conformable sensors that can be mounted on a test material and, for example, monitor crack initiation under the sensor. A second sensor may be left in air to provide a reference measurement, or the temperature of the material under test can be varied to verify the response of the individual sensing elements. Sensors can be mounted to materials under test in order to not modify the environment that is causing the stress being monitored. A sensor may be flexible to conform to the shape of the surface of the material under test and may be mounted in difficult to access locations such as around fasteners of an aircraft. Spatially periodic field eddy current sensors may be scanned across a material to create images of the absolute material property beneath the sensor.

Capacitive -inductive touch screen

Abstract: A touch screen uses a combination of capacitive sensing and inductive sensing applied to the same sensor pattern. A capacitive sensor uses the electric field formed by the columns and rows of the sensor matrix. An inductive sensor uses the magnetic field formed by current flowing in column and row lines to induce an inductive pen. Using the same sensor lines, the magnetic field created by the oscillating inductive pen is detected. Both methods require no moving elements in the sensor and it is possible to combine both method of detections in the same sensor pattern. Using switch matrices, the sensor lines are operated in an open loop fashion for the capacitive detection mode, and are operated in a closed loop fashion for the inductive detection mode.

Capacitive proximity sensors

Abstract: Capacitive proximity sensors (10) are disclosed that can be fabricated in different shapes, sizes and materials used in a wide variety of applications. Each such sensor includes a sensing electrode (11) and a guard electrode (12). The sensor electrode and guard electrode can be parallel conductors separated by an insulating layer (13), such as a double-sided circuit board shaped to suit the application. One such sensor is transparent for use in conjunction with an optical bar-code scanner. Another sensor is annular in shape for use in conjunction with a telephone transmitter. The sensing electrode and the guard electrode are driven in unison by an RF signal (21). The proximity of an object to the sensor is observed by detecting (in 24) changes in the RF current flowing through the sensing electrode caused by the proximity of an object to the sensing electrode.

High resolution inductive sensor arrays for material and defect characterization of welds

Abstract: A sensor that characterizes welds in materials. The sensor includes a meandering drive winding with at least three extended portions and at least one sensing element placed between an adjacent pair of extended portions. A time varying electric current is passed through the extended portions to form a magnetic field. The sensor is placed in proximity to the test material and translated over the weld region. An electrical property of the weld region is measured for each sensing element location. The weld quality is determined using a feature of the electrical property measurement and location.

A low-cost inductive proximity sensor for industrial applications

Abstract: In this paper,we present an inductive proximity sensor with fully integrated electronics. The sensor with the compact hybrid configuration is composed of a sensing flat coil and an integrated electronic interface. We focused during the development on the temperature stability and robustness of the sensor by keeping its low-fabrication cost. The sensor exhibits a longitudinal resolution of 120 nm for an aluminum target position up to 500um from the sensing coil with the side size of 3.5 mm. The temperature drift of the sensor is less than 700 ppm/◦C for the same range of the target position. The total working range is from 100 to 1500um. The sensor power consumption is 100mW and the active sensor dimensions are 3.5mm×3.5mm×1.2 mm.We also showed the facility of the sensor packaging. This kind of integrated sensor has the potential for even more industrial applications.