Chapter 6 Flashcards
What type of disturbances activate fence disturbance sensors?
Cutting or moving the wires
How do fence electric field or capacitance sensors differ from fence disturbance sensors?
They activate when an intruder approaches the wires due to a change in capacitance coupling.
How is the sensor activated in taut wire sensors?
By deflection in the wires
What initiates a signal in fiber optic cable sensors in the fence disturbance category?
L W D (m_____ b_____)
Light wave disturbances (micro-bending)
What can defeat fence disturbance sensors?
Bridging over or tunneling under the fence
What is the detection range of fence electric field or capacitance sensors in terms of distance beyond the wires?
3.3 feet (1 m)
How can sensor fences be less likely to have a high nuisance alarm rate?
By good grounding of the electric sensors
What considerations should be taken into account for designing a control workstation?
Adjustable lighting, temperature, humidity, noise, and comfort features to reduce fatigue and frustration.
Where are displays typically located in a control workstation?
In the center of the console, not requiring much head or eye movement.
How can audible signals be used to alert the operator in a control workstation?
Different pitches and sounds to distinguish various types of alarms.
What can a Graphical User Interface (GUI) improve in a control workstation?
The display of security alarm information.
What are some rules mentioned for designing control workstations regarding color usage?
Limiting colors to 7, using consistent shades for menus/buttons, and considering color-blindness.
What is contraband and give examples of contraband materials?
Materials not permitted in an area, such as weapons, explosives, drugs, recording devices.
What is the main advantage of using manual searches for contraband detection?
Low cost compared to other detection methods.
Why might metal detection be an important part of contraband detection?
It can detect weapons made of steel, a common material choice.
What is a magnetometer used for in contraband detection?
To monitor the Earth’s magnetic field and detect changes.
What are some limitations of using metal detection for contraband detection?
Inability to detect non-ferromagnetic metals like copper, aluminum, zinc.
What is the wavelength of infrared energy used in active infrared sensors?
About 0.9 microns.
How does an active infrared sensor reduce vulnerability to intruders jumping over or crawling under the detection beams?
By forming a ‘fence-like’ beam pattern with multiple aligned beams.
What are some vulnerabilities of active infrared sensors?
Vulnerable to fog, snow, dust storms, can be defeated by various tactics.
What type of energy does Exterior Passive Infrared (PIR) detect?
Changes in heat (thermal energy) in the protected area.
What is important for mounting Exterior Passive Infrared sensors to maintain detection capabilities?
Mounting the sensors where intruders will cross them.
What is a drawback of Exterior Dual Technology sensors?
Individual technology detection probability reduced.
How is the combined detection probability calculated for a dual-technology sensor?
Multiply the individual technology detection probabilities.