Which of the following is a function performed by intrusion detection sensors?

• A. Intrusion motion detection
• B. Intruder penetration
• C. Operator violation
• D. The movement of protected property within the space

Answer: (A)

Intrusion detection sensors are designed to detect unauthorized entry by sensing movement, openings, or tampering at entry points and then triggering an alarm. This is their primary function: to alert security personnel or systems when a breach occurs, so immediate action can be taken. They don’t perform acts like penetrating a person (intruder) themselves, creating operator violations, or tracking the movement of assets within a space. Those activities are outside the sensor’s role; they’re more about entry detection and alerting rather than physically moving people or items, or monitoring operator behavior. Examples include motion detectors, door/window sensors, and glass-break sensors, all aimed at sensing intrusion events and signaling a response.