Smart UV light

The system has been designed for use in the field on already installed solar modules with the aim of providing a quick and easy way to locate microcracks. The use during module logistics (for example in warehouses) is possible for previously used/installed modules, for brand-new modules the test approach does not work, more on this below.

The "Smart UV-light" uses fluorescence effects when irradiated with UV light, which are then analyzed by the viewer. The system itself is designed for maximum optical performance and long operation time of 5 hours due to its high battery capacity.


General Data

  • Lightsource (2x High-performance UV LED)
  • Wavelength range in UV-A
  • Optical power: 2x 1 W / Electrical power: 2x 4 W
  • Radiation angle: 60°
  • Riskgroup concerning EN 62471: 3
  • Light duration: 4 - 5 h
  • Battery (2x Li-Ion Type 18650)
  • Nominal capacity: 4400 mAh
  • Nominal voltage: 7,4 V
  • Charger
  • 1x EU-plug (100-240 V AC, 50/60 Hz) with 12 V charging voltage and 1 A charging current
  • 1x Car-plug (12-24 V DC) with 12-24V charging voltage and max. 2A charging current

Large-scale analysis by UV-Fluorescence

Unlike conventional imaging techniques (such as electroluminescence), the use of UV fluorescence technique does not examine the individual solar cell itself, but the EVA used to encapsulate the cells. This laminating material is used to protect the solar cells from physical forces and the weather.

As a result of solar radiation, fluorescent fission products are generated in the material, which can be oxidized again by contact with oxygen and thus lose their fluorescence capability. Cell damage (such as microcracks) will damage EVA encapsulation and allow oxygen to enter. Thus, defective areas can be easily recognized by a lack of fluorescence.

This fast and simple method of measurement is suitable for large-scale investigations of entire systems and is also used for pre-detecting the modules for a subsequent EL field measurement.