An Electronic Packaging Approach to Improving an Environmental Sensor and Sensing Technique

Abstract

The most common type of electronic packaging, the printed circuit board (PCB), is also useful for realizing low-cost environmental sensors for applications such as measuring increases in the salinity of water. Salts adhering to relocated coastal sand can leach into and contaminate freshwater bodies. When adjusted for temperature, the presence of the leached salt in freshwater can be detected by measuring the accompanying increase in electrical conductivity (EC) of the resulting aqueous solution. To estimate the increase in EC from salt leaching from a mass of sand, a technique was developed based on using a low-cost planar PCB sensor, 2 g of the sand, and 125 mL of distilled water. Using the sensor, the electrical conductance is measured in the distilled water, in the distilled water with 1 g of added sand, and in the distilled water with 2 g of added sand. After a line is fitted to a plot of the three data points, the slope of that line represents an estimate of the expected increase in electrical conduc...