Advanced detection of initial state of iron rust based on dual-mode sensing of a touch-type corrosion sensor with magneto supply

Some nondestructive diagnostic methods, including various types of corrosion sensors, have been investigated. Under these conditions, a new sensor structure that is composed of a pair of electrodes and a magneto supply is proposed. Dual-mode sensing, surface-mode sensing and penetration-mode sensing, based on two different characteristics of the monostructural sensor are realized by changing the direction of the magnetic field. The sensor, in the surface mode with a large impedance, detects first the initial state of iron rust, and then the corrosion state of the iron rust which was detected in the surface mode is diagnosed in the penetration mode with high precision. As a result, an advanced instrumentation of the touch-type corrosion sensor using dual-mode sensing is anticipated.