Matches in SemOpenAlex for { <https://semopenalex.org/work/W321629533> ?p ?o ?g. }
Showing items 1 to 95 of
95
with 100 items per page.
- W321629533 abstract "This article describes a new probe technology with enhanced flaw detection capability, which through the use of multiple magnetic field sensing elements, can also reduce inspection time. The probe contains a linear array of high-sensitivity Hall sensors and a racetrack coil. Instead of using individual Hall sensors to form the array, sensor arrays were fabricated directly on a wafer using photolithography techniques and then mounted in their unencapsulated form. The array dimensions are chosen to achieve high spatial resolution and to limit the overall probe size. Individual active elements have a minimum separation of 400 μm and a sensitive region 50 μm across. Electronic hardware and custom software have been developed to interface the new probes to a computer. Modulation of Hall current was introduced to discriminate the Hall signal from the effects of inductive pick-up and to improve signal to noise ratio. INTRODUCTION Conventional eddy current inspection uses induction coils to detect cracks and other flaws but it has been suggested recently that inductive probes are reaching their development limits and that new sensors are needed to push back the present boundaries of flaw detection [1]. For subsurface flaws such as cracks under fasteners in aircraft skins, the performance of inductive 69 sensors is limited by the need to use low frequencies to achieve significant penetration. Induction coil signals, being dependent on the rate of change of flux linkage, are less effective at low frequencies whereas typical solid state sensors do not suffer a diminished sensitivity in the low frequency regime. In a driver pick-up probe configuration, a relatively large coil can be used as a driver and high spatial resolution plus good low frequency performance achieved by using small solid state devices as sensors. Because the solid state sensors are easily fabricated as arrays, we can take advantage of this to produce probes that facilitate faster inspections. Although coil arrays have been successfully produced and tested, additional turns of wire are needed for subsurface flaw detection to improve the low frequency performance. However, this increases their size and reduces the spatial resolution of the probe [2]. Arrays made with individual Hall sensor integrated circuits (ICs) and a rectangular coil have been produced [3] but the integrated circuit package is much bigger than the actual Hall element therefore the spacial separation of the devices is limited by the packaging. The probes described in this article overcome these difficulties. We also describe electronic hardware and custom software developed to interface the probes to a computer. DESIGN OF THE HALL SENSOR ARRAYS The Hall sensors, type P2, grown by a molecular beam epitaxy (MBE) system on a 2 inch wafer, were obtained from the University of Manchester Institute of Science and Technology in the United Kingdom. They are new two-dimensional electron gas Hall devices which were designed using the AlGaAs-InGaAs structure shown in Fig A.1. The sensors are designed for low magnetic field measurement of the order 1 μT with a magnetic field amplitude resolution of a few hundred nanoTesla [4]. The characteristics of the P2 Hall sensor are given in Table A.1 [4]. Two types of arrays were fabricated on a single wafer: one with the devices connected in series and the other with them connected in parallel. While the series arrays are suitable for constant current drive, its input resistance is very high. The arrays in parallel are suitable for constant voltage drive and have low input resistance which requires a low supply voltage." @default.
- W321629533 created "2016-06-24" @default.
- W321629533 creator A5085489082 @default.
- W321629533 date "2018-08-13" @default.
- W321629533 modified "2023-10-16" @default.
- W321629533 title "Defect detection using eddy-currents and Hall effect sensor arrays" @default.
- W321629533 cites W1599498522 @default.
- W321629533 cites W1639172435 @default.
- W321629533 cites W17622182 @default.
- W321629533 cites W1964120383 @default.
- W321629533 cites W1972683174 @default.
- W321629533 cites W2004129285 @default.
- W321629533 cites W2005872310 @default.
- W321629533 cites W2010985301 @default.
- W321629533 cites W2022417227 @default.
- W321629533 cites W2035473487 @default.
- W321629533 cites W2047325142 @default.
- W321629533 cites W2085576744 @default.
- W321629533 cites W2086663937 @default.
- W321629533 cites W2100788482 @default.
- W321629533 cites W2156319784 @default.
- W321629533 cites W2287501396 @default.
- W321629533 cites W3047590038 @default.
- W321629533 doi "https://doi.org/10.31274/rtd-180813-16057" @default.
- W321629533 hasPublicationYear "2018" @default.
- W321629533 type Work @default.
- W321629533 sameAs 321629533 @default.
- W321629533 citedByCount "0" @default.
- W321629533 crossrefType "dissertation" @default.
- W321629533 hasAuthorship W321629533A5085489082 @default.
- W321629533 hasBestOaLocation W3216295332 @default.
- W321629533 hasConcept C102130693 @default.
- W321629533 hasConcept C102998134 @default.
- W321629533 hasConcept C107637996 @default.
- W321629533 hasConcept C108572070 @default.
- W321629533 hasConcept C119599485 @default.
- W321629533 hasConcept C119857082 @default.
- W321629533 hasConcept C121332964 @default.
- W321629533 hasConcept C127413603 @default.
- W321629533 hasConcept C131357438 @default.
- W321629533 hasConcept C134112204 @default.
- W321629533 hasConcept C135403697 @default.
- W321629533 hasConcept C160671074 @default.
- W321629533 hasConcept C16389437 @default.
- W321629533 hasConcept C199360897 @default.
- W321629533 hasConcept C21200559 @default.
- W321629533 hasConcept C24326235 @default.
- W321629533 hasConcept C24890656 @default.
- W321629533 hasConcept C2779843651 @default.
- W321629533 hasConcept C30403606 @default.
- W321629533 hasConcept C41008148 @default.
- W321629533 hasConcept C6441794 @default.
- W321629533 hasConcept C66251956 @default.
- W321629533 hasConcept C69990965 @default.
- W321629533 hasConceptScore W321629533C102130693 @default.
- W321629533 hasConceptScore W321629533C102998134 @default.
- W321629533 hasConceptScore W321629533C107637996 @default.
- W321629533 hasConceptScore W321629533C108572070 @default.
- W321629533 hasConceptScore W321629533C119599485 @default.
- W321629533 hasConceptScore W321629533C119857082 @default.
- W321629533 hasConceptScore W321629533C121332964 @default.
- W321629533 hasConceptScore W321629533C127413603 @default.
- W321629533 hasConceptScore W321629533C131357438 @default.
- W321629533 hasConceptScore W321629533C134112204 @default.
- W321629533 hasConceptScore W321629533C135403697 @default.
- W321629533 hasConceptScore W321629533C160671074 @default.
- W321629533 hasConceptScore W321629533C16389437 @default.
- W321629533 hasConceptScore W321629533C199360897 @default.
- W321629533 hasConceptScore W321629533C21200559 @default.
- W321629533 hasConceptScore W321629533C24326235 @default.
- W321629533 hasConceptScore W321629533C24890656 @default.
- W321629533 hasConceptScore W321629533C2779843651 @default.
- W321629533 hasConceptScore W321629533C30403606 @default.
- W321629533 hasConceptScore W321629533C41008148 @default.
- W321629533 hasConceptScore W321629533C6441794 @default.
- W321629533 hasConceptScore W321629533C66251956 @default.
- W321629533 hasConceptScore W321629533C69990965 @default.
- W321629533 hasLocation W3216295331 @default.
- W321629533 hasLocation W3216295332 @default.
- W321629533 hasOpenAccess W321629533 @default.
- W321629533 hasPrimaryLocation W3216295331 @default.
- W321629533 hasRelatedWork W1564487137 @default.
- W321629533 hasRelatedWork W2348486298 @default.
- W321629533 hasRelatedWork W2363355623 @default.
- W321629533 hasRelatedWork W2376592058 @default.
- W321629533 hasRelatedWork W2394132630 @default.
- W321629533 hasRelatedWork W2502664435 @default.
- W321629533 hasRelatedWork W2782477859 @default.
- W321629533 hasRelatedWork W2947210162 @default.
- W321629533 hasRelatedWork W3168339984 @default.
- W321629533 hasRelatedWork W616820151 @default.
- W321629533 isParatext "false" @default.
- W321629533 isRetracted "false" @default.
- W321629533 magId "321629533" @default.
- W321629533 workType "dissertation" @default.