A basic experimental grading device aiming at development of a grading machine for Chinese dried green raisins was made on a trial basis.
    The grading discrimination of dried rasins being transported by a belt conveyor using a color image sensor and a digital fiberoptic sensor clearly showed that the accuracy of grading by the color image sensor was not affected by conveyance speed. On the other hand, the accuracy of the digital fiberoptic sensor was dependent on conveyance speed. Based on the results of these experiments, an experimental grading device for dried green raisins was able to efficiently separate raisins into three grades: excellent, fair and substandard. The experimental grading device using a color image sensor for grade detection was able to make a 95% or higher comprehensive discrimination.

Keywords: Chinese dried green raisin, color image sensor, digital fiberoptic sensor, discrimination ratio, grading