| 摘要 |
<p>At least one detector unit (18) is located on the seed supply line (4) between the seed container and sowing nozzles, comprising a first light source (24) on one side of the line and a second light source (30) on another side of the line for shining parallel beams of light in the same plane at right angles to the seed flow direction along the line and over the entire line cross- section. A first linear camera (28) is located on the opposite side of the line to the first light source and a second linear camera (34) is located on the opposite side of the line to the second light source so that the cameras can detect light from the two light sources over their entire width. The cameras are connected to a control unit (20) which compares the level of light across the width of the camera over time in order to count the number of seeds which have passed the detector unit. The light sources comprise lasers. Air is used to supply the seeds from the container to the nozzles.</p> |
