FABRICATION AND TESTING OF GYPSUM BLOCKS FOR SOIL MOISTURE DETERMINATION

Abstract

Over the last decade, many new developments of soil moisture sensors have been evolved, especially those based on the frequency domain reflectometry (FDR) capacitance technique, due to the rapid developments in the micro- electronics industry. This project work is aimed at field study of gypsum blocks for soil moisture determination. Three types of GBs were fabricated and used in this study. The dimension for GB as given by Michael (1978) was used as reference. The other two sizes were two-third ( ) and one and half ( ) of the Michael’s size. The field evaluation of the three types of GB was carried out to measure soil moisture content. A field area of 3 by 4 m was prepared and three blocks each of the types fabricated were installed. The blocks were installed at 25 cm depth below the soil surface into holes made with augers. The block was calibrated using a log-log graph and exponential function to obtain the relationship between moisture content and resistance as . The equation was used to evaluate the resistance based moisture content. The result shows that there is a variation in the moisture content using different sizes of blocks.

Keywords: fabrication, testing, soil moisture

DOI: 10.7176/JNSR/9-3-09