Which anti-masking technology is described as most reliable?

• A. Passive infrared anti-mask
• B. Microwave anti-mask
• C. Acoustic masking
• D. Active infrared anti-mask is the most reliable

Answer: (D)

Reliability of anti-masking technology comes from whether the detector actively verifies masking with its own signal or relies on ambient cues. Active infrared anti-mask sends out a continuous infrared beam and watches for disruptions. When someone tries to mask or block the sensor, the tampering is detected by the system itself, making it quick and less affected by surrounding conditions. In contrast, passive infrared anti-mask depends on heat patterns from a person, which can be fooled by clothing, nearby heat sources, or changes in environment, reducing reliability. Acoustic masking relies on sound, which can be masked by noise or muffled by the attacker, leading to false or missed detections. Microwave anti-mask uses radar signals; while robust, it can face interference and require careful calibration. Because it provides a direct, self-contained indication of masking, active infrared anti-mask is generally the most reliable choice.