Anti-masking technology that is described as most reliable is which option?

• A. Active infrared anti-mask
• B. Passive infrared anti-mask
• C. Microwave anti-mask
• D. Acoustic masking

Answer: (A)

Active infrared anti-mask is the most reliable because it actively checks the lens area with its own infrared signal rather than just watching the scene. By emitting IR light and continuously monitoring how it returns, the system can quickly and confidently detect when the lens is being obstructed or a mask is placed over it. This active verification works well across different lighting and temperature conditions and is less prone to being fooled by background changes.

In contrast, passive infrared anti-mask relies on the natural heat in the scene and doesn’t actively confirm that the lens is clear, making it more susceptible to false readings in varying temperatures. Microwave anti-mask can be affected by interference and material properties, and acoustic masking depends on sound cues that are easily disrupted by noise. So, the active IR approach provides a more consistent and dependable detection of masking.