Counterfeit currency is a significant global issue that affects economies and businesses. Detecting fake notes is crucial for minimizing losses, and one of the most effective tools for this purpose is the UV flashlight. 1. Working Principle of UV Flashlights in Currency Detection UV flashlights emit ultraviolet (UV) light, typically in the 365nm to 395nm wavelength range. Many genuine currencies have embedded security features that fluoresce under UV light. Counterfeit notes often lack these features or replicate them poorly, making them easily detectable. Aspect Details Wavelength 365nm to 395nm is ideal for detecting fluorescent materials. Fluorescent Features Embedded fibers, watermarks, [...]