Chapter 5 Flashcards
What is the purpose of barriers? (3)
- Restrict or impede access
- Provide continuous protection
- Deter threats
What are 3 things about barriers
- They can be natural or man-made
- They can include animals, humans
- They can include dispensable barriers
What are generally more resistant than to penetration than door, windows or other openings
Walls
What results in placing two or more walls in a series (close proximity)
A longer penetration time than one wall of the same thickness
What is specific about hinges on the exterior side of a door?
They should be non-removable hinges or have the hinge pins welded in place
What dimensions does a window need to be away from the ground or trees to require protection?
If it is below 18 feet from the ground, is less than 14 feet from the trees or larger than 96 square inches
What type of material is not generally recommended for security applications?
Acrylics (Lucite/plexiglas) that are less than 1 inch think and than can be penetrated in less than 10 seconds
What is the purpose of window film?
It strengthens the glazing from breakage, blasts, or ballistic penetration.
How much can window film strengthen glass?
more than 300 times it’s original strength and offer 5 times more heat resistance
What size opening should receive protection measures
Anything greater than 96 inches
What are protection measures for building openings?
steel bars, grills, wire mesh, expanded metal or fencing material
Why is it beneficial to install roof enhancements below the roofline?
It is more cost effective and more effective against penetration
What is a fence or wall designed to do? (3)
- Define an area
- Delay and intruder
- Direct people or vehicles to desired checkpoints/entrances
What is the most commonly used security application?
chain linked fencing
What is the medium security fence height and why?
7 feet. It is the minimum height to deter human penetration
What is the required dimensions of chain link fence fabric?
9 AWG or heavier with mesh openings not greater than 2 square inches
What does a typical fence top guard consist of and what does it do?
- There are 3 strands of twisted double strand barbed wire with 4-point barbs spaced equal distance apart.
2, The 3 strands of barbed wire are 6 inches apart - A 3 strand top guard typically increases the fence height by 1 foot.
What is the difference between active and passive blocking barriers?
Active barriers must always be attended and must have standard operating procedures developed
What is bollard height?
typically not more than 30 inches high but never higher than 38 inches in height
How much must a safe weigh to be anchored to the ground?
750 pounds or less
What is the criteria for fire resistant safe?
heating the safe and dropping it 30 feet and reheating and retesting the safe for internal temperatures
What are the hour ratings for a fire resistant safe for paper protections?
1, 2, and 4 hours only (not 3 hours)
How much space of illumination is sufficient to detect human movement?
A minimum of 175 yards
What parameters should protective lighting allow to identify faces and individuals at night?
human face at 33 feet and notice individuals at 75 feet or more away
What 3 main purposes does protective lighting serve?
- It can be a psychological deterrent to intruders
- It enables detection, assessment, and identification
- It supports or enhances the video surveillance system
Where is high mast lighting used?
In outdoor applications such as parking lots and along highways and usually are 70 to 150 feet in height.
What is a Metal Halide lamp and what is it best used for?
It is a high intensity arc tube in which the light is produced by the radiation of excited metal halides. It works well with video surveillance systems.
What is Low Pressure Sodium and what is it not recommended to be used for?
It is a high intensity discharge arc in which light is produced by radiation from sodium vapor operating under pressure. Due to its poor rendition this lamp is not recommended for security operations.
What percentage should reflectance of light be and why?
100% because the closer it is to 100 percent the better the quality of images.
How should the illumination of light be characterized?
By light to dark ratio:
Ideally should be 4:1
but maintained at No less than 6:1
What are typical uniformity ratios for illumination of light for
- working environments
- on a pedestrian walkway
- on a roadway
- working environments- 1:0.7
- on a pedestrian walkway- 4:1
- on a roadway- 10:1
What is the minimum reflective light for the purposes of pedestrian human camera surveillance for
Detection
Recognition
Identification?
Detection- 0.5 FC
Recognition- 1.0 FC
Identification- 2.0 FC
What percentage does a color camera need of it’s full video signal?
50%
What percentage does a black and white camera need of it’s full video signal?
20-30%
What are the costs associated with a lighting system?
8 percent capital items, 4 percent maintenance costs, 88 percent energy cost
When should group replacement of lamps be considered?
When the lamps get to 80% of their rated life
