Solar neutrino: Difference between revisions
Jump to navigation
Jump to search
en>Davidallred No edit summary |
en>AnomieBOT m Dating maintenance tags: {{Page needed}} |
||
| Line 1: | Line 1: | ||
The '''troland''' (symbol '''Td'''), named after [[Leonard T. Troland]], is a unit of ''conventional retinal illuminance''. It is meant as a method for correcting [[photometry (optics)|photometric]] measurements of [[luminance]] values impinging on the [[human eye]] by scaling them by the effective [[pupil]] size. It is equal to retinal illuminance produced by a surface whose luminance is one [[Nit (unit)|nit]] when the apparent area of the entrance pupil of the eye is 1 square milimeter. <ref> [http://www.answers.com/topic/troland answers.com]</ref> | |||
The troland typically refers to the ordinary or [[photopic]] troland, which is defined in terms of the photopic luminance: | |||
:<math> \mathrm{T} = \mathrm{L} \times \mathrm{p} </math> | |||
where ''L'' is the photopic luminance in [[candela|cd]] [[square metre|m<sup>-2</sup>]] and ''p'' is pupil area in mm<sup>2</sup> | |||
A [[scotopic]] troland is also sometimes defined: | |||
:<math> \mathrm{T'} = \mathrm{L'} \times \mathrm{p} </math> | |||
where ''L′'' is the scotopic luminance in [[candela|cd]] [[square metre|m<sup>-2</sup>]] and ''p'' is pupil area in mm<sup>2</sup> | |||
== Conversions to other units== | |||
{| class="wikitable" | |||
|- | |||
| 1 troland || 10 kcd/m^2 (kilocandelas per square meter) | |||
|- | |||
| || 10000 cd/m^2 (candelas per square meter) | |||
|- | |||
| || 1×10^7 mcd/m^2 (millicandelas per square meter) | |||
|- | |||
| || 1×10^10 mucd/m^2 (microcandelas per square meter) | |||
|- | |||
| || 1 cd/cm^2 (candela per square centimeter) | |||
|- | |||
| || 3.142 La (lamberts) (unit officially deprecated) | |||
|- | |||
| || 2919 footlamberts (unit officially deprecated) | |||
|- | |||
| || 2919 equivalent foot-candles (unit officially deprecated) | |||
|- | |||
| || 31416 blondels (unit officially deprecated) | |||
|- | |||
| || 10000 nit (nits) (unit officially deprecated) | |||
|- | |||
| || 3.142×10^7 skots (unit officially deprecated) | |||
|- | |||
| || 1 stilb (unit officially deprecated) | |||
|} <ref name=wolframalpha.com>[http://www.wolframalpha.com/input/?i=troland wolframalpha.com] </ref> | |||
==Conversions from Other Units== | |||
{| class="wikitable" | |||
|- | |||
|1 kcd/m^2 || 0.1 trolands | |||
|- | |||
|1 cd/m^2 || 1×10^-4 trolands | |||
|- | |||
|1 mcd/m^2 || 1×10^-7 trolands | |||
|- | |||
|1 mucd/m^2 || 1×10^-10 trolands | |||
|- | |||
|1 cd/cm^2 || 1 troland | |||
|- | |||
|1 La || 0.3183 trolands | |||
|- | |||
|1 footlambert || 3.426×10^-4 trolands | |||
|- | |||
|1 equivalent foot-candle || 3.426×10^-4 trolands | |||
|- | |||
|1 blondel || 3.183×10^-5 trolands | |||
|- | |||
|1 nit || 1×10^-4 trolands | |||
|- | |||
|1 skot || 3.183×10^-8 trolands | |||
|- | |||
|1 stilb || 1 troland | |||
|} <ref name=wolframalpha.com /> | |||
==Physical quantities== | |||
* luminance | |||
*equivalent luminance <ref name=wolframalpha.com /> | |||
==Unit system== | |||
centimeter-gram-second (cgs) <ref name=wolframalpha.com /> | |||
==Unit status== | |||
officially deprecated <ref name=wolframalpha.com /> | |||
==Basic unit dimensions== | |||
[length]^(-2) [luminous intensity] <ref name=wolframalpha.com /> | |||
==Comparisons== | |||
* ≈ 0.8 × luminance of a kerosene candle (≈ 12000 cd/m^2 ) | |||
* ≈ luminance of a sperm candle (≈ 10000 cd/m^2 ) | |||
* ≈ luminance of an average daytime clear sky (≈ 8000 cd/m^2 )<ref name=wolframalpha.com /> | |||
==See also== | |||
*[[Leonard T. Troland]] | |||
*[[Troland Research Awards]] | |||
==References== | |||
{{reflist}} | |||
[[Category:Photometry]] | |||
[[Category:Vision]] | |||
[[Category:Non-SI metric units]] | |||
[[Category:Units of illuminance]] | |||
Revision as of 23:53, 25 October 2013
The troland (symbol Td), named after Leonard T. Troland, is a unit of conventional retinal illuminance. It is meant as a method for correcting photometric measurements of luminance values impinging on the human eye by scaling them by the effective pupil size. It is equal to retinal illuminance produced by a surface whose luminance is one nit when the apparent area of the entrance pupil of the eye is 1 square milimeter. [1]
The troland typically refers to the ordinary or photopic troland, which is defined in terms of the photopic luminance:
where L is the photopic luminance in cd m-2 and p is pupil area in mm2
A scotopic troland is also sometimes defined:
where L′ is the scotopic luminance in cd m-2 and p is pupil area in mm2
Conversions to other units
| 1 troland | 10 kcd/m^2 (kilocandelas per square meter) |
| 10000 cd/m^2 (candelas per square meter) | |
| 1×10^7 mcd/m^2 (millicandelas per square meter) | |
| 1×10^10 mucd/m^2 (microcandelas per square meter) | |
| 1 cd/cm^2 (candela per square centimeter) | |
| 3.142 La (lamberts) (unit officially deprecated) | |
| 2919 footlamberts (unit officially deprecated) | |
| 2919 equivalent foot-candles (unit officially deprecated) | |
| 31416 blondels (unit officially deprecated) | |
| 10000 nit (nits) (unit officially deprecated) | |
| 3.142×10^7 skots (unit officially deprecated) | |
| 1 stilb (unit officially deprecated) |
Conversions from Other Units
| 1 kcd/m^2 | 0.1 trolands |
| 1 cd/m^2 | 1×10^-4 trolands |
| 1 mcd/m^2 | 1×10^-7 trolands |
| 1 mucd/m^2 | 1×10^-10 trolands |
| 1 cd/cm^2 | 1 troland |
| 1 La | 0.3183 trolands |
| 1 footlambert | 3.426×10^-4 trolands |
| 1 equivalent foot-candle | 3.426×10^-4 trolands |
| 1 blondel | 3.183×10^-5 trolands |
| 1 nit | 1×10^-4 trolands |
| 1 skot | 3.183×10^-8 trolands |
| 1 stilb | 1 troland |
Physical quantities
- luminance
- equivalent luminance [2]
Unit system
centimeter-gram-second (cgs) [2]
Unit status
officially deprecated [2]
Basic unit dimensions
[length]^(-2) [luminous intensity] [2]
Comparisons
- ≈ 0.8 × luminance of a kerosene candle (≈ 12000 cd/m^2 )
- ≈ luminance of a sperm candle (≈ 10000 cd/m^2 )
- ≈ luminance of an average daytime clear sky (≈ 8000 cd/m^2 )[2]
See also
References
43 year old Petroleum Engineer Harry from Deep River, usually spends time with hobbies and interests like renting movies, property developers in singapore new condominium and vehicle racing. Constantly enjoys going to destinations like Camino Real de Tierra Adentro.