The use of a SQUID for quantitative magnetic field measurements in the nanoTesla region for eddy current NDE
نویسنده
چکیده
In this paper the use of a HTS SQUID magnetometer for quantitative measurements in eddy current NDE is presented. The SQUID is used in absolute rather than in gradiometric mode and the magnetic field measurements are directly compared to theoretical results. The measurements are taken in an ambient noise environment and the excitation has the form of a double-rectangle Printed Circuit Board coil. The configurations examined involve the coil in air and above Aluminum plates with or without defects in the form of long through-thickness slots. The agreement between experimental and theoretical results is very good showing that model-based calculations and optimizations of SQUID magnetometers are feasible.
منابع مشابه
High Tc SQUIDs for Unshielded Measuring in Disturbed Environments
Directly coupled dc SQUID gradiometers on the basis of YBqCu,O, for unshielded NDE measurements are investigated. The influence of different SQUID layout parameters on the field sensitivity is shown. A sensitivity of 500 ffl(crn.JHz) is achieved with a baseline of 3.6 mrn. A slit in an aluminium plate was detected in an demonstration of NDE in 1 cm depth with eddy current method.
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