Orthogonal optimization design of structural parameters for interdigital sensor

Interdigital sensors are widely used in nondestructive testing for physical properties of manufactures, with the advantages of one-side access, controllability of signal strength, imaging capability, etc. The paper analyzes characteristic indices and structural parameters. The orthogonal optimization design and regression analysis is proposed based on the half-wavelength model and three-dimensional model. The optimal structure parameters is chosen. The results show the characteristic of the sensor with optimal parameters is improved. A three-wavelength interdigital sensor with the optimum structure parameters is developed using printed circuit board. Crosstalk between channels is analyzed and experiment is carried on. The result shows the error caused by crosstalk between three channels is less than 0.8%.