🔍 Key Concepts

• Fluorescent dye penetrant testing principles • How materials appear under ultra-violet (black) light • Typical color response of common fluorescent leak-detection dyes

💭 Think About

• When a fluorescent dye is exposed to UV light, what part of the spectrum does it usually emit—toward green, red, purple, or orange? • Think about common fluorescent leak detection kits used in refrigeration or hydraulic systems: what color glow do they usually produce? • Which of the colors listed is most commonly associated with "high-visibility" safety and inspection under black light?

✅ Before You Answer

• Verify which color is most commonly used in industrial fluorescent leak-detection dyes. • Consider which color stands out most clearly in low light under UV illumination. • Eliminate any colors that are not typically associated with standard fluorescent inspection dyes.