Intrusion Detection & Monitoring Flashcards
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Read the first 7 Intrusion Detection & Monitoring flashcards as text
A technician is programming an alarm control panel and needs to set the entry delay. Which of the following best describes the entry delay's purpose?
Answer: Time given to an authorized user to disarm the system after entering through a designated door
The entry delay provides a defined window—typically 30 to 60 seconds—for authorized users to enter through a designated entry point and disarm the system before an alarm is triggered.
In video analytics used for intrusion detection, what is a 'virtual tripwire'?
Answer: A software-defined line in a camera's field of view that triggers an alert when crossed
A virtual tripwire is a user-defined line drawn within a camera's field of view; the analytics engine triggers an alert when an object crosses the line in a specified direction.
Which factor most significantly degrades the performance of a passive infrared (PIR) detector?
Answer: Ambient temperature approaching normal body temperature
PIR detectors sense differential infrared radiation between a moving body and its background; when ambient temperature approaches body temperature (~98.6°F), the contrast diminishes and detection reliability drops.
A central monitoring station receives a 'troubles' signal from an alarm panel. What does this signal typically indicate?
Answer: A system fault condition such as low battery, AC power loss, or communication failure
Trouble signals indicate supervisory fault conditions within the system—such as low battery, loss of AC power, or a zone fault—rather than an active intrusion event.
When integrating an intrusion detection system with access control, which event pairing provides the strongest verification of unauthorized entry?
Answer: Door forced open alarm AND motion detected in the secured area
Correlating a door forced-open event with motion detected inside the secured zone provides strong confirmation of unauthorized physical entry without a valid credential.
Under NFPA 731, who is qualified to perform the final acceptance test of an intrusion alarm system?
Answer: A qualified alarm technician, often verified by an industry certification such as ESA NTS or equivalent
NFPA 731 requires acceptance testing to be performed by personnel qualified in alarm systems, typically demonstrated through certifications such as the ESA National Training School (NTS) or equivalent credentials.
A technician installs a photoelectric beam detector along a 500-foot fence line. At installation, what initial adjustment is most critical for reliable operation?
Answer: Precisely aligning the transmitter beam with the center of the receiver lens
Precise optical alignment of the transmitter beam with the receiver lens is critical; misalignment reduces signal margin, increasing susceptibility to false alarms and missed detections over long distances.