UPF ultrasonic fork sensors used in production of photovoltaic foils

The new UPF-A sensors from SNT Sensortechnik AG are used in the production of novel flexible photovoltaic foils. Existing silicon based photovoltaic cells are deposited on glass, which is heavy and fragile. The new partially transparent polyimide films are subjected to vacuum coating processes and rolled up at the end. The low weight and mechanical flexibility opens completely new fields of solar electric power generation.

Between each process the film has to be brought back to the correct position. Here works the ultrasonic edge sensor with analog output type UPF-A. It gives a linear signal (0…10V) in function of the web edge position. The signal is then used by the machine control to slightly tilt the next roll until the foil runs again in the middle of the sensor. This is a permanent control process in the 1/10 mm range.

The ultrasonic sensors are here very much superior to conventional optical through beam sensors because they can detect the edges of transparent or partially transparent material without problems.

SNT Sensortechnik AG is a specialist in ultrasonic sensors for more than 20 years.