Date of this Version
Transactions of the ASABE Vol. 58(5), pp 1185-1190
Detecting and measuring agricultural material flow is important in a wide range of applications in agricultural engineering, such as material handling, food processing, yield monitoring, and fertilizer spreading. In these applications, flow rate is determined by measuring material mass or volume as a function of time. Although different materials require detection, the methods for a given material type (e.g., granular) can be similar. Researchers have developed methods such as impact based sensors, radiometric-based sensors, and optical methods to detect and measure material flow. Abdul Rahim and Green (1998) studied an optical-fiber sensor (containing 32 light sources and 32 light detectors) in a tomographic measurement system to measure the flow of dry solids (sand or 3 mm plastic chips) in a gravity-drop system with an 81 mm diameter pipe and pneumatic conveyor. Their results showed linearity between flow rate and output voltage up to 0.5 kg s-1 mass flow rate. They concluded that increasing the number of optical-fiber sensors resulted in better accuracy, and the sensors had a linear response to the increased concentration of solids.