Investigation of the Electrical Capacitance Tomography System for Determining the Spatial Distribution of Moisture in Grain Storage

Abstract

Excessive moisture content (MC) in stored grains promotes the growth of fungi and molds, which affects the quality of the grains. Effective grain monitoring methods are essential for detecting and managing grain spoilage. Electromagnetic imaging (EMI) techniques provide a promising alternative to traditional techniques by visualizing the spatial distribution of moisture within grains rather than merely average MC values offered by traditional techniques. However, existing EMI approaches often use hard-field waves, which are expensive and fragile. This study introduces an Electrical Capacitance Tomography (ECT) system that employs soft-field waves to monitor the moisture content of the grains. The system was calibrated against the oven drying method to establish equations correlating MC with its voltage output. The system was adapted for image reconstruction using the Perspex materials of known shapes. Then, the ECT system was further adapted for spatial moisture visualization using two ECT image reconstruction algorithms. Results showed that the ECT system produced clear images of known shapes of Perspex materials and effectively visualized moisture distribution in grain samples within the sensor. The proposed approach represents a significant advancement in grain storage technology, offering a robust tool for improving grain monitoring and management practices.