Sensing Liquids in Challenging Bottling Applications
Common Challenges in Liquid Detection
The bottling industry has found detecting liquid presence and verifying levels challenging, particularly in two specific applications: detecting clear water in clear bottles and detecting liquid in frosted, colored or decorated bottles. In the past, these applications have been inconvenient and expensive to solve.
When an optical sensor is used to detect water in a clear container, the low contrast will cause the sensor to see the bottle and water as the same item, yielding inconsistent, faulty sensing results. On the other hand, when liquid is contained within a bottle that is partially opaque, the contrast between the bottle and liquid is extremely high. However, many optical sensors cannot burn through dark plastics or colored bottles. High excess gain is required for such applications, and such high excess gain will also easily cut through the enclosed liquid, thereby delivering insufficient sensing results.