Which of the following is a disadvantage of wet aqueous suspendible developer?

• A. Indications weaken and become diffused after time
• B. Indications bright and sharp
• C. White coating for good contrast can be produced
• D. Easy to coat entire part

Answer: (A)

In liquid penetrant testing, the developer helps pull penetrant out to the surface so flaws become visible against a contrasting background. A wet aqueous suspendible developer is water-based and forms a white coating that can give good contrast and cover surfaces relatively easily. The trade-off is that, because it’s water-based, it can continue to move or diffuse after application. Moisture and time cause the dissolved components to spread, which blurs the indications and makes them appear weaker and less defined as the defect signals diffuse. That time- and diffusion-related behavior is what makes this type disadvantageous. The other statements describe benefits you’d expect from a white, easily applied developer, not drawbacks.