Sentence examples for steradian from inspiring English sources

Candela (cd), unit of luminous intensity in the International System of Units (SI), defined as the luminous intensity in a given direction of a source that emits monochromatic radiation of frequency 540 × 1012 hertz and has a radiant intensity in that same direction of 1/683 watt per steradian (unit solid angle).

The candela is defined as the luminous intensity in a given direction of a source that emits monochromatic radiation at a frequency of 540 × 1012 hertz and that has a radiant intensity in the same direction of 1/683 watt per steradian (unit solid angle).

The quantity of light flux flowing out from a source is measured in lumens, the lumen being defined as the amount of flux radiated by a small "point" source of one candle power into a cone having a solid angle of one steradian.

Derived from the Greek for solid and the English word radian, a steradian is, in effect, a solid radian; the radian is an SI unit of plane-angle measurement defined as the angle of a circle subtended by an arc equal in length to the circle's radius.

This unit of luminous intensity is also called the standard candle, or candela, one lumen per steradian.

The unit of luminous intensity is one lumen per steradian, which is the unit of solid angle there are 4π steradians about a point enclosed by a spherical surface.

Lumen, unit of luminous flux, or amount of light, defined as the amount streaming outward through one steradian (a unit of solid angle, part of the volume of space illuminated by a light source) from a uniform point source having an intensity of one candela.

Steradian, unit of solid-angle measure in the International System of Units (SI), defined as the solid angle of a sphere subtended by a portion of the surface whose area is equal to the square of the sphere's radius.

Since the complete surface area of a sphere is 4π times the square of its radius, the total solid angle about a point is equal to 4π steradians.