Proximity Sensing for Metals, Using an Amorphous Wire C-MOS MI Circuit

Abstract

This paper presents a new proximity sensing method for metals that uses a C-MOS IC MI sensor circuit with an amorphous wire head 30 μm in diameter and 1-2 mm in length with a coil. A sharp pulse field with a rise time of a few nano seconds is generated from the amorphous wire by a coil current and the wire axis, and induces a field with an eddy current at the surface of a metal specimen. The new metal sensor with a micro-size head and quick response is expected to be useful for non-destructive testing (NDT) of micro region in metals.