False Rejects for stuck ware on the main camera.
A): The angle of the conveyor belt.
If the conveyor belt is under an angle, possibly the camera sees bottles that are close to each other as stuck ware. This effect is caused by the fact that the camera is a line scanner; The left bottom corner of the first bottle which passes the camera can be in the same line scan as the right top corner of the second bottle due to the belt angle. Or vice versa, depending on the direction of the bottles with respect to the camera. This effect causes bad splitting.
B): Dirty Filter glass.
Dirty filter glass (purple haze in the image) gives a bad contrast in the image. In turn this results in bad splitting (check threshold level in the splitting chart) and causes false rejects.
A): Use ‘manual splitting’ instead of ‘semi-automatic’ in the splitting chart. Semi-automatic splitting uses the whole bottle image to determine the splitting. Manual splitting uses a small part of the image which in this case is better.
B): Clean the IR-Filter glass or change the easy-clean filter glass if you have the easy-clean camera version.