Sukanthi: "{{anchor|table-si-photometry-units}} {| class="wikitable plainrowheaders" |+ {{navbar-header |1={{resize|130%|{{#if:{{{1|}}}|Table {{{1}}}. }}SI photometry quantities}}|2=SI light units}} |- ! scope="col" colspan="2" | Quantity ! scope="col" colspan="2" | Unit ! scope="col" rowspan="2" | Dimension
{{#tag:ref|The symbols in this column denote Dimens..."-இப்பெயரில் புதிய பக்கம் உருவாக்கப்பட்டுள்ளது

2025-09-22T06:38:52Z

"{{anchor|table-si-photometry-units}} {| class="wikitable plainrowheaders" |+ {{navbar-header |1={{resize|130%|{{#if:{{{1|}}}|Table {{{1}}}. }}SI photometry quantities}}|2=SI light units}} |- ! scope="col" colspan="2" | Quantity ! scope="col" colspan="2" | Unit ! scope="col" rowspan="2" | Dimension<br>{{#tag:ref|The symbols in this column denote Dimens..."-இப்பெயரில் புதிய பக்கம் உருவாக்கப்பட்டுள்ளது

புதிய பக்கம்

{{anchor|table-si-photometry-units}}
{| class="wikitable plainrowheaders"
|+ {{navbar-header |1={{resize|130%|{{#if:{{{1|}}}|Table {{{1}}}. }}SI photometry quantities}}|2=SI light units}}
|-
! scope="col" colspan="2" | Quantity
! scope="col" colspan="2" | Unit
! scope="col" rowspan="2" | Dimension<br>{{#tag:ref|The symbols in this column denote [[Dimensional analysis#Definition|dimensions]]; "'''L'''", "'''T'''" and "'''J'''" are for length, time and luminous intensity respectively, not the symbols for the [[Unit of measurement|units]] litre, tesla and joule.|group={{#if:{{{3|}}}|{{{3}}}|nb}}|name=note-dimension-symbol}}
! scope="col" rowspan="2" | Notes
|-
! scope="col" | Name
! scope="col" | Symbol{{#tag:ref|[[Standards organization]]s 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|group={{#if:{{{3|}}}|{{{3}}}|nb}}|name=note-suffix-v}}
! scope="col" | Name
! scope="col" | Symbol
|-
! scope="row" | [[Luminous energy]]
| {{math|''Q''{{sub|v}}}}{{#tag:ref|Alternative symbols sometimes seen: {{mvar|W}} for luminous energy, {{mvar|P}} or {{mvar|F}} for luminous flux, and {{mvar|ρ}} for luminous efficacy of a source.|group={{#if:{{{3|}}}|{{{3}}}|nb}}|name=note-alternative-symbol-photometric}}
| [[lumen second]]
| [[lumen (unit)|lm]]⋅s
| '''T'''⋅'''J'''
| The lumen second is sometimes called the ''talbot''.
|-
! scope="row" | [[Luminous flux]], luminous power
| {{math|Φ{{sub|[[Luminosity function|v]]}}}}{{#tag:ref||group={{#if:{{{3|}}}|{{{3}}}|nb}}|name=note-alternative-symbol-photometric}}
| [[lumen (unit)|lumen]] (= candela [[steradian]])
| lm (= cd⋅sr)
| '''J'''
| Luminous energy per unit time
|-
! scope="row" | [[Luminous intensity]]
| {{math|''I''{{sub|v}}}}
| [[candela]] (= lumen per steradian)
| [[candela|cd]] (= lm/sr)
| '''J'''
| Luminous flux per unit [[solid angle]]
|-
! scope="row" | [[Luminance]]
| {{math|''L''{{sub|v}}}}
| [[candela per square metre]]
| cd/m{{sup|2}} (= lm/(sr⋅m{{sup|2}}))
| '''L'''{{sup|−2}}⋅'''J'''
| Luminous flux per unit solid angle per unit ''projected'' source area. The candela per square metre is sometimes called the ''[[nit (unit)|nit]]''.
|-
! scope="row" | [[Illuminance]]
| {{math|''E''{{sub|v}}}}
| [[lux]] (= lumen per square metre)
| [[lux|lx]] (= lm/m{{sup|2}})
| '''L'''{{sup|−2}}⋅'''J'''
| Luminous flux ''incident'' on a surface
|-
! scope="row" | [[Luminous exitance]], luminous emittance
| {{math|''M''{{sub|v}}}}
| lumen per square metre
| lm/m{{sup|2}}
| '''L'''{{sup|−2}}⋅'''J'''
| Luminous flux ''emitted'' from a surface
|-
! scope="row" | [[Luminous exposure]]
| {{math|''H''{{sub|v}}}}
| [[lux second]]
| lx⋅s
| '''L'''{{sup|−2}}⋅'''T'''⋅'''J'''
| Time-integrated illuminance
|-
! scope="row" | Luminous energy density
| {{math|''ω''{{sub|v}}}}
| lumen second per cubic metre
| lm⋅s/m{{sup|3}}
| '''L'''{{sup|−3}}⋅'''T'''⋅'''J'''
|
|-
! scope="row" | [[Luminous efficacy]] (of radiation)
| {{math|''K''}}
| lumen per [[watt]]
| lm/[[watt|W]]
| '''M'''{{sup|−1}}⋅'''L'''{{sup|−2}}⋅'''T'''{{sup|3}}⋅'''J'''
| Ratio of luminous flux to [[radiant flux]]
|-
! scope="row" | [[Luminous efficacy]] (of a source)
| {{mvar|η}}{{#tag:ref||group={{#if:{{{3|}}}|{{{3}}}|nb}}|name=note-alternative-symbol-photometric}}
| lumen per [[watt]]
| lm/[[watt|W]]
| '''M'''{{sup|−1}}⋅'''L'''{{sup|−2}}⋅'''T'''{{sup|3}}⋅'''J'''
| Ratio of luminous flux to power consumption
|-
! scope="row" | [[Luminous efficiency]], luminous coefficient
| {{mvar|V}}
|
|
| '''1'''
| Luminous efficacy normalized by the maximum possible efficacy
|-
| style="text-align:center;" colspan=6 | See also: {{hlist|class=inline|[[SI]]|[[Photometry (optics)|Photometry]]|[[Radiometry]]{{#if:{{{2|}}}|{{!}}([[{{#ifeq:{{{2}}}|self||Radiometry}}#table-si-radiometry-units{{!}}Compare]])}}}}
|}{{#if:{{{3|}}}||{{Reflist|group=nb}}}}<noinclude>

{{documentation}}



</noinclude>

வார்ப்புரு:SI light units - திருத்த வரலாறு