Sensors and CCD-cameras
Color sorter, optical (or optoelectronic) sorter, or just a sorter- these all mean one and the same machine for the sorting.
Despite the differences in terminology, modern color sorters differ in design, dimensions, price and production capacity. In general though, design, behavior, setting parameters, operating panel and user interface are similar for all color sorters of different manufacturers. Nevertheless there is a crucial distinguishing feature in optical system design which triggers a lot of disputes, a color sorter with sensors and a color sorter with CCD cameras.
To understand where the difference between these types of sorters is, it is necessary to recollect the system of object analysis since due to this system the color sorting process becomes possible.
Input product for sorting is loaded in the sorter via in-feed hopper. With the help of vibration, the material flows along the chute to the distribution channels. Then the product gets into the inspection zone, where it is viewed by the signal analyzer. In the first case, this analyzer is the sensor, in the second case- CCD cameras, while sensors view the grain over its whole surface (total spot) thus averaging the general information flow, the image received from CCD matrix is point-like.
Depending on the signals received from the optical system, the computer control system sends the command to open the pneumatic valve (the ejector) which blows away grains different from the pre-set grain parameters. The good product directly flows into the good product hopper. The reject is blown off to the discharging hopper.
Since CCD cameras view the grain point-like, they are able to delete to reject the grains with small defects, what becomes important when sorting sunflower seeds with split and fractured grains etc. Although such accuracy is required not for each enterprise since during the production of the roasted sunflower seeds, losses of the whole but split along seeds put at stake the revenues. In this case such sunflower seed is considered a good product. Analyzing the product with contaminant with background differences instead of spot ones it is logical to apply sensor color sorters.
Another difference is that each sensor in the sensor color sorter inspects its own channel, while CCD camera in the CCD camera sorters views the whole width of the chute. It potentially makes sensor color sorters more reliable in operation, since the breakdown of one sensor leads to the breakdown of one channel, however breakdown of one camera may lead to the breakdown of the whole machine (in case of 1-chute color sorter)
Selecting the appropriate model, we recommend you to pay attention to the specific sorting goals rather than color sorter model and on the basis of your goals chose the right model.