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EntityQ901492· pop 20· linked from 35 articles

Also known as ph

A phot (ph) is a photometric unit of illuminance, or luminous flux through an area. It is not an SI unit but rather is associated with the older centimetre–gram–second system of units. The name was coined by André Blondel in 1921.

Key facts

Unit.name
Phot
Unit.standard
CGS units
Unit.quantity
Illuminance
Unit.symbol
ph
Unit.units1
SI derived unit
Unit.units2
SAE units
Unit.inunits2
929 fc

via Wikipedia infobox

~1 min read

Encyclopedic overview

3 sections
Contents
  • See also
  • References
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A phot (ph) is a photometric unit of illuminance, or luminous flux through an area. It is not an SI unit but rather is associated with the older centimetre–gram–second system of units. The name was coined by André Blondel in 1921.

Metric equivalence: 1\ \mathrm{phot} = 1\ \frac{\mathrm{lumen}}{\mathrm{centimetre}^2} = 10,000\ \frac{\mathrm{lumens}}{\mathrm{metre}^2} = 10,000\ \mathrm{lux} = 10\ \mathrm{kilolux}

Excerpted from Wikipedia’s “phot” article, available under the CC BY-SA 4.0 licence.