عنوان مقاله [English]
نویسندگان [English]چکیده [English]
This project was established to develop a procedure for the selection, design, installation, test and evaluation of mass-flow rate measurement systems for root crop (potatoes and sugar beet) harvesting. To assess consistency and precision of the weighing systems incorporated with crop feed arrangements, laboratory and field studies were conducted. Studies were conducted to evaluate conveyor belt weighing systems using an experimental apparatus and commercial potato harvester. Two weighing systems were evaluated: (a) cantilever transducers fitted to the conveyor belt mechanism and (b) a load cell system supporting the total weight of the conveyor and crop. The results of laboratory studies with sugar beet/potatoes showed that the standard cantilever transducers and the load cell supporting systems gave the smallest percentage of standard deviation from the mean experimental error, with values equal to 0.54 and 0.84 kg, respectively. Experiments were conducted in the laboratory and field to assess the effects of belt inclination and extraneous vibration, transferred from the tractor to the harvester, on the measurements of crop mass. The results of field studies with potatoes using the cantilever transducers showed that the most accurate system performance was when using the 125 mm idler wheels with standard deviation of the mean experimental error of the sample yield equal to 0.98 kg. The results of barn field studies with potatoes using the load cell system showed that there was a good linear relationship between the indicated and weighed mass of the potato samples with standard deviation of the mean experimental error equal to 0.34 kg.