Definition

Noun: - Luminous intensity measured in candelas: Candlepower is a unit of measurement for the luminous intensity of a light source, based on the light emitted by a standard candle. It is essentially equivalent to one candela.

Usage

• Technical/Scientific Context: The term is used in physics, engineering, and lighting design to quantify the brightness of a light source as perceived by the human eye in a specific direction.
  • The lamp's beam has a maximum candlepower of 10,000.
  • Older specifications for flashlights often listed their output in candlepower.

Advanced Usage

• Mean Spherical Candlepower (MSCP): A measure of the total luminous flux of a light source, averaged over all directions.
  • The bulb's mean spherical candlepower is used to calculate its total light output.
• Candlepower Distribution Curve: A graphical representation showing how the intensity of a light source varies in different directions.
  • The engineer analyzed the fixture's candlepower distribution curve to avoid glare.

Variants and Related Words

• Candela (n): The modern SI base unit of luminous intensity, which officially replaced the term "candlepower" in most precise contexts. One candela is approximately equal to one candlepower.
• Luminous Intensity (n): The general physical quantity that candlepower and candela measure.
• Lumen (n): A unit of total luminous flux, related to but distinct from candlepower, which measures intensity in a particular direction.

Synonyms

• Luminous intensity (the measured quantity itself, not the unit).
• Light intensity (a more general, less technical term).

Notes on Usage

• The term candlepower is considered somewhat dated in formal scientific use, having been largely superseded by the SI unit candela (cd). However, it is still encountered in certain industries, historical contexts, and informal specifications.
• It is a non-count noun; one typically refers to "100 candlepower" not "100 candlepowers."

Noun

1. luminous intensity measured in candelas