Performance of Coating Materials on Planar Electromagnetic Sensing Array to Detect Water Contamination

This paper looked into the electrical properties of contaminants via planar electromagnetic sensing array (PESA), which had been coated with various types of coaters, namely, N-Methyl-2-pyrrolidone-based membrane and acrylic. Hence, the performance of the coaters had been evaluated based on the minimal difference of estimated results, which was later compared with an Agilent 85070 dielectric probe instrument. Three samples were selected for this paper, namely, nitrate, phosphate, and nickel solutions. These samples were prepared based on varied concentration levels, including 5, 25, 75, and 100 ppm. Besides, the theory for the sensor equivalent to circuit described the calculations to determine the aspects of permittivity and conductivity of the water samples. The results demonstrated that both coaters successfully estimated the electrical properties of the contaminants. The relative permittivity of all samples using the PESA coated with membrane displayed similar trends for the dielectric probe, but a slight variance was present for the PESA coated with acrylic. In fact, the relative permittivity of the nitrate sample ranged from 65 to 78 when the estimation was made using PESA coated with membrane, whereas the acrylic coater demonstrated that the relative permittivity data varied from 0.198 to 41.100. Hence, the acrylic coater failed in precision, thus inappropriate for relative permittivity estimation. Nonetheless, both coaters shared similar pattern for conductivity even with varied concentrations. However, the conductivity increased as the sample concentration increased. As such, this paper concludes that the PESA coated with membrane exhibited better performance compared with acrylic in estimating electrical properties.