Locally Half Bridged Resistant Type Moisture Content Predicting Device for Grains

Abstract

The percentage of moisture in grains is a parameter essential in controlling the market value, rate of drying and control of chemical and fungi activities. The importation into Nigeria of the so called sophisticated moisture meters which are calibrated differently for conditions cost lots of foreign exchange. This paper presents a Nigerian made resistance type moisture measuring device for grains with four copper cup electrodes out of which two were used as the gauging electrodes while the other two electrode cups were used as dummies giving the half (1/2) Wheatstone bridge configuration to measure %moisture contents on dry basis of three different grains namely paddy rice, guinea corn and millet during drying. The predictive empirical relationships between the resistance and percentage moisture content generated after comparison with the direct oven method suggest that the locally developed device could predict the moisture content of grains once it has been calibrated.The high negative coefficients of correlation (ϒ) between the resistance and percentage moisture content obtained for the paddy rice, Guinea Corn and Millet tested were respectively -0.88308,-0.94033 and -0.53088.