Lumber, Patterned
Lumber that is shaped to a pattern or to a molded form.
Lumber, Matched
Lumber that is edge dressed to make close tongue-and-groove edge joints.
Lumber, Shiplapped
Lumber that is edge dressed to make a lapped joint.
Lumber, Rough
Lumber that has not been surfaced but may be sawn, edged, and trimmed.
Lumber, Dressed Size
The size of lumber after it has been cut to size and the surfaces planed.
Lumber, Nominal Size
The size of lumber after it has been sawn to size but has not been surfaced.
Lumber, Dimension
Lumber cut and dressed to standard sizes.
Lumber, Shop and Factory
Lumber intended to be cut up and used in some manufacturing process.
Lumber, Machine Stress-Rated
Lumber that has been mechanically tested to determine its stiffness and bending strength.
Lumber, Boards
Lumber nominally less than 2 inches thick and 2 inches or more in width.
Luminescence
The emission of light not directly caused by incandescence.
Luminous Flux
The rate of flow of light energy through a surface, expressed in lumens.
Lumber, Structural
Lumber that is intended for use where allowable strength or stiffness of the piece is known.
Luminous Transmittance
A measure of the capacity of a material to transmit incident light in relation to the total incident light striking it.
Lumen
A unit for measuring the flow of light energy.
Luminance Meter
A photoelectric instrument used to measure luminance. Also called a light meter.
Lumens
Unit of measure for total light output. The amount of light falling on a surface of one square foot.
Luminaire
A complete lighting unit consisting of one or more lamps plus elements needed to distribute light, hold and protect the lamps, and connect power to the lamps. Also called a lighting fixture.
Luminous Intensity
The force that generates visible light express by candela, lumens per steradian, or candlepower.
Luminance
the luminous intensity of a surface of a given area viewed from a given direction.