The specific process I am dealing with now is sifting ingredients for a baking process. Essentially, I am trying to sort out clumps and foreign objects. In an ideal case, all product would make it through the screens and nothing would be rejected.
If a screen is damaged, the undesirable items could make it through to the product. So, if the reject product were monitored (by weighing or some other means), it would be difficult to determine if the process was operating well (no rejects) or if the screen was damaged (no rejects).
Today, processors visually inspect the screens periodically. We have been challenged by a customer to see if we can come up with some kind of alarm or notification in the event that a screen is damaged.
I appreciate the thoughts!