A German chemist invented a more efficient vacuum pump in 1865 which was critical to the development of incandescent light bulb.

First developed a working incandescent light bulb using carbon-filament lamp in February 5, 1879.

First announced the successful development of an incandescent lamp with a baked carbonized cotton thread filament in December 21, 1879.

On August 26, 1985, the Niagara Falls Power Company became the first commercial utility to produce and transmit hydroelectric power.

In 1939, General Electric introduced fluorescent lighting, an electric light source that is more efficient than the incandescent lamp.

Most light sources emit electromagnetic energy composed of different wavelengths of light.

_____ is the amount of light incident on (striking) a surface.

_____ is how bright an object appears.

______ is the ratio of reflected light versus the light striking the surface.

_____ is ratio of light transmitted through body to light illuminating surface.

_____ is the ratio of the light absorbed versus the light striking the surface.

A _____ light source emits a fairly even distribution of all wavelengths of light.

A _____ light source produces visible light in a very small range of wavelengths.

The colors of pigments are magenta (purplish red), cyan (greenish blue), and yellow which are opposite of the colors of light.

Light Output: Luminous flux is the measure of the perceived power of light expressed in lumens (Im).

A _____ is defined as the quantity of light given out through a steradian by a source of one candela of intensity radiating equally in all directions.

A _____ is the luminous intensity, in a given direction.

Luminous _____ is the ratio of the light output of a light source (a specific lamp) to the electrical energy consumed to produce the light source

The rated life of a lamp is its maximum life expectancy, expressed in hours

Ballast is a voltage transformer and current-limiting device designed to start properly control the flow of power to discharge light sources such as fluorescent and HID lamps

The phosphor blend in a lamp determines the color temperature and color rendering of the light emitted by the lamp.

- Sometimes called “task lighting’.

- Illumination provided for specific visual function.

- Can influence the effectiveness of the individual performing the task.

Is directional lighting used to emphasize a particular object or area.

Ensures the safety of people involved in a potentially hazardous process.

Illuminated signage used to provide clear directions for an emergency exit of building occupants.

a luminaire that is hang 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.

is a luminaire where a shielded light source directs its light to the ceiling, where it is reflected back to the space.

a type of downlight that is a recessed, canister-shaped luminaire with a shielded lamp that emits light downward.

are mounted above the ceiling or behind a wall or other surface so that any visible projection of light is insignificant.

High Bay Luminaires are used in high-ceiling areas, 20 m (6 ft) or higher, that require uniform illumination.

is 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.

Floodlight a luminaire that emits a mild light that is broader than a spotlight and that is capable of being pointed in any direction.

a lighting installation where the light source is shielded by a panel that is parallel to the wall and attached to the ceiling; it distributes light over the wall.

an uplighting installation where the light source is shield by a ledge or recess with light dispersed over the ceiling and upper wall.

a lighting installation where the light source is shielded by a panel that is parallel to the wall at the top of a window.

Distribution of Light: 90 to 100% of the light is directed to the ceilings and upper walls and is reflected to all parts of a room or 90 to 100% of the light is directed downward for maximum use.

Distribution of Light: 60 to 90% of the light is directed downward with the remainder directed upward.

causes visual discomfort without necessarily impairing vision.

Inverse square law states that the illuminance at a point on a plane parallel to the line joining the point and a source is inversely proportional to the square of the distance between the source and the plane.

Cosine law of incidence states that illuminance (E) at a point on a plane is proportional to the cosine of the angle of light incidence, where the angle of light incidence is measured between the direction of the incident light and the normal to the plane of the surface.

The zonal cavity method is the currently accepted method for calculating average illuminance levels for indoor areas unless the light distribution is extremely symmetric.

A room is made up of three spaces called _____. The space between the luminaires and the work plane is referred to as the _____; the space between the work plane and the floor is called the _____; and the space between the ceiling and the luminaires (if they are suspended) is defined as the _____.

switches are a simple on/off switch that controls a lighting installation from one location.

can be circuited to control a lighting installation from two or more locations.

A central lighting control system offers building operators full control of multiple lighting installations from a single location.

Daylighting strategies must be designed to provide illumination in areas where it is most needed and to do so without adversely affecting occupant comfort.

A basic daylighting strategy is to increase the number and size of glazed areas in the walls or ceilings of a building, but simply using large glazed openings does not ensure good daylighting.

Polyvinyl chloride-polyester and Teflon-coated woven fiberglass fabrics are commercially available fabric roof membranes that have been used successfully.