Experimental determination of optimum coil pitch for a planar mesh type micro-magnetic sensor for the evaluation of near-surface material properties

Summary form only given. For the evaluation of the near-surface material properties (e.g. conductivity, permeability, thickness etc.) the use of planar type meander magnetic sensors has already been reported. In order to overcome the directional properties of meander type sensor, a new type of sensor having mesh configuration has been fabricated in the laboratory. A two-dimensional analytical model of one pitch of the sensor has been developed for the calculation of transfer impedance and other parameters. The weakness of the edge effect is impossible to overcome in the analytical model. This paper reports the selection of optimum pitch based on the experimental data. Five type of sensors having pitches of 1.4 mm, 1.8 mm, 2.1 mm, 2.6 mm and 3.25 mm have been fabricated and experiments are carried out.