Automatic Lens Identification for Thermographic Cameras

Measuring high-resolution thermographic images requires accurate radiometric calibration (assignment of temperature to measured value) of the camera to the optics used. The lenses in particular have a significant influence on this calibration. Infrared (IR) cameras without automatic detection of the attached lens are prone to errors when selecting the correct calibration range after a manual lens change. In order to address this problem, a reliable and user-friendly approach is introduced to minimize errors due to lens mix-ups or incorrect operation by the customer and during in-house calibration. This is achieved by developing a system for automatic lens identification on thermographic cameras. To this end, contactless and contact-based variants of lens-body data transmission are researched and evaluated to application-specific criteria. Functional tests of a contactless radio-frequency identification (RFID) solution delivered very reliable data transmission results and demonstrated the possibility to incorporate the method in a prototype.