Application examplesControl of fill levels for microtiter plates – coating processes
Microtiter plates made of polystyrene with curved or flat wells are used as a testing platform in diagnostic laboratories, for example in serology or hematology (blood type identification). The manufacturers of such analytical tests fill the wells of the microtiter plates or strips with the necessary reagents during the manufacturing process (e.g. proteins, antibodies, pathogen components) to load the plastic surface of the wells.
To ensure even loading of the plates or strips, the fill level of the microtiter plates is monitored after filling and checked for possible air bubbles and dirt particles. If any are present, their number and size are analyzed.
Up to 96 wells are measured via transmitted or reflected light with the help of a special camera. Analysis of individual well positions selected by the user is also possible. The plate is removed from the production process if defined cut-off values are exceeded.
Label control for location, print quality and information content
The accuracy of such product information as data, batch codes, expiration or production dates cannot be guaranteed without continuous verification.
Various printed data represented by special codes (EAN128 barcode, Data Matrix and plain text) can be automatically verified on product labels. The label position may vary up to several millimeters, with an angle that might additionally shift by up to five degrees. The image processing system first registers the location of the label, then positions the measurement windows to read the print. The subsequent verification procedure checks and reports the presence, number and readability of all characters.
Characters may be printed or applied in many different forms and various fonts, shapes and orientations. The combination of powerful VMT algorithms, filters and real color image processing, together with high-performance OCR/OCV tools ensures the greatest possible character recognition quality and reliability.
Automated inhibition zone measurement for active ingredient tests
Inhibition zones are inspected using indirect transmitted light with an appropriate camera. The insertion and adjustment of the petri dish by the lab technician is followed first by determining the inhibition zone midpoints. The “hole test” procedure determines the midpoint via calculation of the midpoint of the punched hole, while the “cylinder test” procedure relies on measurement of the zone of inhibition itself.
Determination of the surface area of the inhibition zone involves multiple-stage circular ring detection. The diameter is calculated using the measured inhibition zone surface area with an assumed circle approximation. Determination of active ingredient concentration in meeting standards is also possible.