Lighting Flashcards
What is CCT?
Corrected Color Temperature is a measure of the warmth or coolness of a light.
What are the 6 general protective lighting types?
1) Continuous-uniform lighting in hours of darkness
2) Glare Projection (deters intruders by making it difficult to see into an area and easy to see the intruders)
3) Standby lighting-Lighting that can be turned on for random intervals (deterrent) or when suspicious activity may be occurring
4) Controlled-Lighting that illuminates a limited space
5) Portable-Moveable search lights
6) Emergency-limited to times of power failures, needs alternate power
What is the CRI?
Color-Rendering Index:
Measures the effects of light on the appearance of objects.
Scale is 0 to 100.
The higher the number the better it is.
What is Efficacy?
Lumens per watt. A measurement of efficiency specific to lighting
What are the three main purposes of Protective lighting?
1) Psychological Deterrent
2) Detection
3) Enhances Video Surveillance
What are the five security lighting categories?
1) Streetlight
2) Searchlight (lights up a specific area)
3) Floodlight
4) Fresnel (long horizontal beam)
5) High Mast
What are the ten lamp types?
1) Incandescent (Instant startup, cheap, good for colour, but short life, high heat, inefficient)
2) Quartz/Quartz-Halogen (incandescent, but filled with halogen gas, 25% more efficient)
3) Fluorescent (gas enclosed tube, 75-100 CRI, twice as efficient as incandescent)
4) Mercury Vapour (Long life, low cost for install, (50 CRI)
5) Metal Halide (arcs the halides, most expensive light, 70 CRI)
6) High Pressure Sodium (light radiates from vapour when energized, long lie, highly efficient, CRI 20)
7) Low Pressure Sodium (yellowish light not recommended for video surveillance 5 CRI)
8) Light Emitting Diode (high initial cost, 75-90 CRI)
9) Induction Diode (similar to florescent, but longer lifespan CRI 100)
10) Infrared (only used with monochrome cameras, no CRI)
What are two methods to limit loss of lighting in a critical area.
1) Dual circuiting of poles
2) Alternate circuiting of Fixtures
What are the costs associated with lighting systems?
8% for Capital costs
4% for maintenance
88% for energy
What is the coefficient of utilization? What coefficients are required for Detection, Recognition, and Identification?
The ratio of light to a surface.
Detection: 0.5 FC
Recognition: 1 FC
Identification: 2.0 FC
What are the 3 considerations for matching lighting with cameras?
1) CRI (some cameras are designed for a specific CRI range)
2) Illuminance (reflected light)
3) Directionality
When should group replacement of lamps be considered?
at 80% of the lamps rated life.
