UVF is highly effective for detecting material related degradation such as encapsulant changes, moisture pathways, delamination, and aging effects within the module layers. However, UVF does not detect every type of defect. Cell level cracking and internal electrical issues are often better evaluated using EL testing. Because solar module failure can involve multiple mechanisms, UVF is often best used as part of a broader diagnostic approach that may include EL imaging, infrared scans, and electrical testing depending on the nature of the concern.