Chapter 20 Flashcards
When did Thomas Edison announce the successful development of incandescent lamp with a baked carbonized cotton thread filament?
December 21, 1879
Branch of physics that relates to the properties of light and the function of vision
Optics
It functions much like a simple, very crude camera.
Eye
Rays of light pass through this transparent part of the eye.
Cornea
Opening of the eye.
Pupil
It surrounds the pupil.
Iris
The inability to distinguish colors.
Color blindness
Form of electromagnetic radiation that allows eye to see.
Light
It is the energy radiated in the form of a wave caused by an electric field interacting with a magnetic field.
Electromagnetic Radiation
Electromagnetic radiation behaves as a group of particles called ______.
Photons
Speed of Light
186,000 miles per second or 300,000,000 meters per second
Measured as the distance from one wave peak to another.
Wavelength
The number of wave cycles per second measured in hertz.
Frequency
On the electromagnetic radiation spectrum, give at least three groups that is not visible with the naked eye.
- Cosmic Radiation
- Gamma Rays
- X-rays
- Ultraviolet
- Infrared Radiation
- Microwaves
- TV waves
- Radio waves
The part of electromagnetic radiation spectrum capable of exciting the retina and ultimately producing a visual sensation.
Visible light
Wavelength of visible light range.
380 nm to 750 nm
The amount of light incident on (striking) a surface.
Illuminance
The amount of light leaving an object.
Luminance
The ratio of reflected light versus the light striking the surface (illuminance).
Reflectance
The ratio of light transmitted through the body versus the light illuminating the surface.
Transmittance
The ratio of the light absorbed versus the light striking the surface.
Absorptance
A body that transmits light through it without distorting the image.
Transparent
A body that transmits light but obscures the image because the light is scattered.
Translucent
It is the light that is widely spread or scattered.
Diffuse Light
It is a strong, directional type of light. It is the type available on a cloudless, sunny day where shadows are well defined.
Direct Light
The ability to distinguish and interpret different wavelengths of visible light.
Color perception
A device that generates light.
Lamp
It is a complete lighting unit, which consists of a lamp (or lamps), lamp socket(s), any lenses, refractors, or louvers, any ballast (or ballasts), and the housing.
Luminaire
It is the luminaire less the lamp(s).
Light fixture
The measure of the perceived power of light expressed in lumens (lm)
Luminous flux
The SI unit of solid angular measure
Steradian (sr)
SI unit of luminous intensity—that is, the power emitted by a light source in a particular direction
Candela (cd)
One candela is equivalent to
One lumen per steradian
The ratio of the light output of a light source (a specific lamp) to the electrical energy consumed (including the ballast if applicable) to produce that light source
Luminous efficacy
Luminous efficacy is expressed in units of _____
lumens per watt of electric power (lm/W)
This lamp emit visible light as a result of heating.
Incandescent Lamp
These are a smaller, brighter, and more expensive version of the incandescent lamp.
Tungsten-halogen lamps
It is the electricity passing through a gas such that it causes the gas to arc
Gaseous discharge
It is composed of a tubular glass bulb that is covered with a thin phosphor coating on its inside surface.
Fluorescent lamp
It produce a very bright light by discharging an arc when electrical current passes through a metal gas contained under high pressure in a glass bulb.
High-intensity discharge (HID) lamps
These are lamps that combine the luminous efficiency of an HID lamp with the good color rendering capability of an incandescent lamp.
Blended lamps
It refers to a type of lighting that uses light-emitting diodes (LEDs), organic light-emitting diode lights (OLEDs), or polymer light-emitting diodes (PLEDs), instead of traditional lighting sources that use an electrical filament or gas inside a glass bulb.
Solid-state lighting (SSL)
Sometimes called general lighting, it provides uniform illumination throughout the space. It softens shadows on people’s faces and provides the illumination for color and texture
Ambient lighting
It is the directional lighting used to emphasize a particular object or area.
Accent Lighting
The light source that adds a quality of interest to the space.
Decorative Lighting
It is required in the critical care and emergency spaces found in hospitals, nursing homes, and police, fire protection, and crisis management areas
Emergency Lighting
It is part of the emergency lighting system. It enables normal activities to continue substantially unchanged.
Stand-by lighting
The part of emergency lighting system that ensures the safety of people involved in a potentially hazardous process
Safety lighting
It provides illumination to ensure that an escape route can be effectively identified and used in the case of failure of the normal lighting system
Escape lighting
It is the part of the escape lighting system that includes illuminated signage used to provide clear directions for an emergency exit of building occupants
Exit lighting
It is a luminaire that is hung with a cord, chain, or tube that enables it to be suspended from a ceiling or other support. It broadcasts light over the entire space.
Pendent
It is a luminaire where a shielded light source directs its light to the ceiling, where it is reflected back to the space.
Uplight
It is a luminaire that is usually attached to or recessed in the ceiling and emits a concentrated light downward.
Downlight
A type of downlight that is a recessed, canister-shaped luminaire with a shielded lamp that emits light downward.
High hat
These luminaires are mounted above the ceiling or behind a wall or other surface so that any visible projection of light is insignificant.
Recessed
These are decorative, wall-mounted luminaires that provide ambient illumination.
Sconces
Luminaires that are used in high-ceiling areas
High bay luminaires
These luminaires are more compact. They are designed for use in low- to medium-ceiling areas.
Low bay luminaires
It is the illumination where light received at the work plane or light illuminating an object is incident predominantly from a particular direction.
Directional lighting
A luminaire that is designed to emit an intense, concentrated beam of light with usually no more than a 20° divergence (spread) from where it is directed.
Spotlight
A luminaire that emits an intense light that is broader than a spotlight and that is capable of being pointed in any direction.
Floodlight
A directional lighting installation where luminaires are attached to and are moveable along a metal track.
Track lighting
A lighting installation in which the light on the working plane or on an object is not incident predominantly from a particular direction. Diffused light is cast and disbursed over a large area
Diffused Lighting
A lighting installation where the light source is shielded by a panel that is parallel to the wall and attached to the ceiling.
Cornice Lighting
A lighting installation where the light source is shielded by a panel that is parallel to the wall at the top of a window.
Valance Lighting
It is the excessive brightness in the field of vision that causes discomfort or, in extreme cases, produces a disability from a temporary loss of vision.
Glare
The most essential form of lighting because it is the basic background of light for almost every room
Ambient Lighting
Lighting design that illuminates a specific visual function and can influence the effectiveness of the individual performing the task.
Task or local lighting
Lighting design used to add drama and emphasize a particular object or area
Accent lighting
Lighting design that aesthetically adds interest to the space by blending with other types of lighting to give an overall “feel” to a space.
Decorative Lighting
The transitional space from public to private and exterior to interior.
Entrances
Lighting should make the food, the table setting, and the people look attractive, so excellent color rendition is a must.
Dining spaces
The best light washes the face from all directions, softening shadows
Restrooms/bathrooms
Located in walls of a building, these are the most common method of introducing daylight into the interior building spaces.
Windows
A transparent panel located in a roof opening that allows direct and diffuse sunlight into the building. A roof monitor is a type of skylight system that is a raised, typically triangular shaped, extension of a roof and that has at least one glazed surface.
Skylight
