Why do I get False rejects for Verticality and Shape?

PROBLEM DESCRIPTION:
False Rejects for Verticality and/or Shape.

Possible cause

Changes in the intensity of the glass, caused by (for example) changes in IS-cooling. These changes result in a bad splitting. (See splitting chart).

The bad splitting results in its turn in a not correct border detection followed by false rejects for verticality and shape.

Solution

Put the splitting line on a brighter spot of the bottle to correct border detection.