PSP Intrusion Detection Systems 2 — Questions and Answers
Question 1: What is the purpose of 'alarm verification' in a modern intrusion detection system, and how does it reduce law enforcement response burden?
- Alarm verification automatically dispatches police faster than unverified alarms
- It uses video, audio, or sequential sensor activation to confirm an intrusion before dispatching authorities, reducing false alarms (Correct answer)
- It requires the alarm subscriber to physically verify the premise before police are called
- It allows police to remotely monitor the live alarm system feed
Correct answer: It uses video, audio, or sequential sensor activation to confirm an intrusion before dispatching authorities, reducing false alarms
Alarm verification (using video clips, audio, or two-sensor activation) reduces false dispatches — which constitute 94-98% of US police alarm responses — improving response efficiency and reducing fees.
Question 2: What does 'Grade' mean in the context of EN 50131 intrusion detection system standards used as reference in US security specifications?
- The installation quality rating given by the alarm installer
- The risk level classification (1-4) that determines required system performance and tamper resistance (Correct answer)
- The UL listing category of the alarm control panel
- The number of communication paths from panel to monitoring center
Correct answer: The risk level classification (1-4) that determines required system performance and tamper resistance
EN 50131 Grades 1-4 define increasing levels of risk and required system performance: Grade 1 for low risk, Grade 4 for high risk requiring the highest tamper resistance and redundancy.
Question 3: A passive infrared (PIR) detector is installed near an exterior glass wall. What is the MOST likely source of false alarms in this installation?
- Radio frequency interference from nearby equipment
- Direct sunlight or headlights shining through the glass, causing rapid temperature changes in the detection zone (Correct answer)
- Nearby smoke detectors interfering with the PIR signal
- High humidity condensation on the detector lens
Correct answer: Direct sunlight or headlights shining through the glass, causing rapid temperature changes in the detection zone
PIR detectors sense changes in infrared (heat) energy — sunlight or vehicle headlights shining through glass can rapidly heat objects in the detection zone, mimicking a human body and triggering false alarms.
Question 4: In alarm system design, what is the 'defense in depth' approach to intrusion detection?
- Using only the most expensive sensors available
- Installing multiple sensor types and layers so that an intruder must defeat several independent systems to reach the target undetected (Correct answer)
- Placing all sensors deep inside the facility near the most valuable assets
- Hiring additional security guards to supplement electronic detection
Correct answer: Installing multiple sensor types and layers so that an intruder must defeat several independent systems to reach the target undetected
Defense in depth layers perimeter, exterior, interior, and point protection so that bypassing one detection layer still leaves additional layers that must be defeated, increasing detection probability.
Question 5: What alarm transmission technology offers the MOST reliable path from premises to monitoring center against communication sabotage?
- Standard PSTN (phone line) with dial-up communicator
- Broadband IP-only communication
- Dual-path: cellular + broadband IP with automatic failover (Correct answer)
- Cellular-only communication
Correct answer: Dual-path: cellular + broadband IP with automatic failover
Dual-path communication using both cellular and broadband IP with automatic failover is most resistant to sabotage because cutting one path (phone/cable line) still leaves the cellular path active.
Question 6: According to ASIS guidelines, how long should alarm event logs be retained for commercial and industrial facilities?
- 30 days minimum
- 90 days minimum
- 1 year minimum (Correct answer)
- Indefinitely
Correct answer: 1 year minimum
ASIS recommends retaining alarm event logs for a minimum of 1 year to support investigations, legal proceedings, and trend analysis of alarm patterns.
PSP Intrusion Detection Systems 2
What is the purpose of 'alarm verification' in a modern intrusion detection system, and how does it reduce law enforcement response burden?