Photothermal coating thickness measurement

The measurement method behind the OptiSense success

Contactless, fast and efficient: The photothermal coating thickness measurement is a contactless measurement method for paints, powder coatings and glazes on metallic and non-metallic substrates. The different thermal properties of the coating and the substrate are used to determine the coating thickness.

The surface of the coating is warmed up by a few degrees with a short, intense light pulse and then cools down again by dissipating the heat into deeper areas. The thinner the coating, the faster the temperature drops. The temperature curve over time is recorded with a highly sensitive infrared sensor and converted into the coating thickness.

The light pulse can be generated in various ways. Compared to xenon flash lamps, LEDs and diode lasers offer all the advantages of semiconductor technology such as long service life, high efficiency and absolute shock resistance.

Smaller. Faster. More powerful.

Thanks to the precise measuring spot, the method is also suitable for the smallest components. The coating thickness can even be determined on bending edges, corners and curved surfaces, where conventional measurement technology reaches its limits. Disturbances caused by rough surfaces or material grains are compensated for by optical averaging, so that even pastes and powders can be checked before baking.

The measurement is carried out without contact from a distance of several centimetres. This means that wet and sticky coatings can be measured just as easily as soft and sensitive surfaces. A contamination of the part or the carry-over of coating material is thus excluded in principle.

LARES® – Safety redefined

LARES® stands for a safe LAser Radiation Eye Safety technology and is the intelligent answer to the continuously increasing requirements in the field of personal and eye protection. These safety requirements always have the highest priority, especially in direct handling of lasers. By using the new LARES®-technology in the manufacturing and process industry, people, machines and the environment are reliably protected. The handling and use of the devices can be carried out without the need for documentation and user instruction. Thanks to the LARES® technology, the devices can be used directly and without any restrictions in almost all areas of application.

Thanks to the LARES®-logo on the corresponding OptiSense-products, the safe laser technology can be easily recognized. All devices carrying the LARES®-logo are absolutely safe for the eye - even during prolonged irradiation.

The OptiSense sensor

During the photothermal coating thickness measurement, the surface is briefly heated and then the cooling process is evaluated. OptiSense monitors the temperature already during the warm-up phase to prevent material overheating.