Optical inspection of filter tubes for efficient quality assurance

Quality assurance is important in industrial manufacturing, especially in industries where products are manufactured for critical applications. Filter tubes – also known as edge gap filters or slotted filters – play a decisive role in water treatment, among other things, as their design prevents foreign material, such as sand, from entering the interior without impeding the flow of water. They must therefore have a maximum open filter surface and be resistant to corrosion and deposits. To maintain quality, Imess from Witten is presenting an optical system to check the winding geometry of the component.

Thanks to the use of a high-resolution camera and the application of intelligent image evaluation algorithms, the traditional manual inspection of the tubes, which can lead to inefficiency and potential inaccuracies, is no longer necessary.

The windings of the filter tube are clearly visible in the camera image thanks to the backlighting used, which is located in the tube. The camera and lighting move together along the very narrow filter tube. To enable testing of components with a minimum internal diameter of 18 mm, the lighting was specially manufactured from glass fiber-reinforced plastic. The software developed uses the images to determine the geometry of the windings and compares these with the target values and permissible tolerances. Once the measurement is complete, tolerance overruns and an unwinding graph of the geometry are displayed in the user-friendly software. The results can be transferred to the customer’s system together with the order number and can also be saved in spreadsheet-compatible CSV format.

The inspection concept enables the detection of even the smallest irregularities and defects. This enables early intervention and minimizes the risk of faulty products that could later cause expensive recalls or failures. The optical and therefore non-contact inspection increases production speed without compromising on accuracy. The detailed recording of the measurement results enables traceability and facilitates compliance with quality standards. In addition to this system, the team of engineers, software developers and technicians has been developing individual measuring and testing systems tailored to the testing task as inline solutions and individual measuring stations for the spring, metal and plastics industries as well as customer-specific applications for 25 years. Web: www.imess.com