Bril (unit)
Topic: Physics
From HandWiki - Reading time: 2 min
Short description: Non-SI unit of luminance
The bril is an old, non-SI, unit of luminance. The SI unit of luminance is the candela per square metre.
Unit conversions
See also
| Quantity | Unit | Dimension | Notes | |||||
|---|---|---|---|---|---|---|---|---|
| Name | Symbol[nb 1] | Name | Symbol | Symbol[nb 2] | ||||
| Luminous energy | Qv[nb 3] | lumen second | lm⋅s | T⋅J | The lumen second is sometimes called the talbot. | |||
| Luminous flux, luminous power | Φv[nb 3] | lumen (= candela steradians) | lm (= cd⋅sr) | J | Luminous energy per unit time | |||
| Luminous intensity | Iv | candela (= lumen per steradian) | cd (= lm/sr) | J | Luminous flux per unit solid angle | |||
| Luminance | Lv | candela per square metre | cd/m2 | L−2⋅J | Luminous flux per unit solid angle per unit projected source area. The candela per square metre is sometimes called the nit. | |||
| Illuminance | Ev | lux (= lumen per square metre) | lx (= lm/m2) | L−2⋅J | Luminous flux incident on a surface | |||
| Luminous exitance, luminous emittance | Mv | lux | lx | L−2⋅J | Luminous flux emitted from a surface | |||
| Luminous exposure | Hv | lux second | lx⋅s | L−2⋅T⋅J | Time-integrated illuminance | |||
| Luminous energy density | ωv | lumen second per cubic metre | lm⋅s/m3 | L−3⋅T⋅J | ||||
| Luminous efficacy (of radiation) | K | lumen per watt | lm/W | M−1⋅L−2⋅T3⋅J | Ratio of luminous flux to radiant flux | |||
| Luminous efficacy (of a source) | η[nb 3] | lumen per watt | lm/W | M−1⋅L−2⋅T3⋅J | Ratio of luminous flux to power consumption | |||
| Luminous efficiency, luminous coefficient | V | 1 | Luminous efficacy normalized by the maximum possible efficacy | |||||
| See also: SI · Photometry · Radiometry | ||||||||
- ↑ Standards organizations recommend that photometric quantities be denoted with a subscript "v" (for "visual") to avoid confusion with radiometric or photon quantities. For example: USA Standard Letter Symbols for Illuminating Engineering USAS Z7.1-1967, Y10.18-1967
- ↑ The symbols in this column denote dimensions; "L", "T" and "J" are for length, time and luminous intensity respectively, not the symbols for the units litre, tesla and joule.
- ↑ 3.0 3.1 3.2 Alternative symbols sometimes seen: W for luminous energy, P or F for luminous flux, and ρ for luminous efficacy of a source.
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Licensed under CC BY-SA 3.0 | Source: https://handwiki.org/wiki/Physics:Bril_(unit)17 views | Status: cached on September 10 2024 13:08:12↧ Download this article as ZWI file
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