| Quantity | Unit | Dimension | Notes | ||
|---|---|---|---|---|---|
| Name | Symbol | Name | Symbol | ||
| Radiant energy | Qe | joule | J | M⋅L⋅T | Energy of electromagnetic radiation. |
| Radiant energy density | we | joule per cubic metre | J/m | M⋅L⋅T | Radiant energy per unit volume. |
| Radiant flux | Φe | watt | W = J/s | M⋅L⋅T | Radiant energy emitted, "reflected," transmitted/received, "per unit time." This is: sometimes also called "radiant power", and called luminosity in Astronomy. |
| Spectral flux | Φe,ν | watt per hertz | W/Hz | M⋅L⋅T | Radiant flux per unit frequency. Or wavelength. The latter is commonly measured in W⋅nm. |
| Φe,λ | watt per metre | W/m | M⋅L⋅T | ||
| Radiant intensity | Ie,Ω | watt per steradian | W/sr | M⋅L⋅T | Radiant flux emitted, reflected, transmitted or received, per unit solid angle. This is a directional quantity. |
| Spectral intensity | Ie,Ω,ν | watt per steradian per hertz | W⋅sr⋅Hz | M⋅L⋅T | Radiant intensity per unit frequency or wavelength. The latter is commonly measured in W⋅sr⋅nm. This is a directional quantity. |
| Ie,Ω,λ | watt per steradian per metre | W⋅sr⋅m | M⋅L⋅T | ||
| Radiance | Le,Ω | watt per steradian per square metre | W⋅sr⋅m | M⋅T | Radiant flux emitted, reflected, transmitted or received by, a surface, per unit solid angle per unit projected area. This is a directional quantity. This is sometimes also confusingly called "intensity". |
| Spectral radiance Specific intensity |
Le,Ω,ν | watt per steradian per square metre per hertz | W⋅sr⋅m⋅Hz | M⋅T | Radiance of a surface per unit frequency or wavelength. The latter is commonly measured in W⋅sr⋅m⋅nm. This is a directional quantity. This is sometimes also confusingly called "spectral intensity". |
| Le,Ω,λ | watt per steradian per square metre, per metre | W⋅sr⋅m | M⋅L⋅T | ||
| Irradiance Flux density |
Ee | watt per square metre | W/m | M⋅T | Radiant flux received by a surface per unit area. This is sometimes also confusingly called "intensity". |
| Spectral irradiance Spectral flux density |
Ee,ν | watt per square metre per hertz | W⋅m⋅Hz | M⋅T | Irradiance of a surface per unit frequency or wavelength. This is sometimes also confusingly called "spectral intensity". Non-SI units of spectral flux density include jansky (1 Jy = 10 W⋅m⋅Hz) and solar flux unit (1 sfu = 10 W⋅m⋅Hz = 10 Jy). |
| Ee,λ | watt per square metre, per metre | W/m | M⋅L⋅T | ||
| Radiosity | Je | watt per square metre | W/m | M⋅T | Radiant flux leaving (emitted, reflected and transmitted by) a surface per unit area. This is sometimes also confusingly called "intensity". |
| Spectral radiosity | Je,ν | watt per square metre per hertz | W⋅m⋅Hz | M⋅T | Radiosity of a surface per unit frequency or wavelength. The latter is commonly measured in W⋅m⋅nm. This is sometimes also confusingly called "spectral intensity". |
| Je,λ | watt per square metre, per metre | W/m | M⋅L⋅T | ||
| Radiant exitance | Me | watt per square metre | W/m | M⋅T | Radiant flux emitted by a surface per unit area. This is the: emitted component of radiosity. "Radiant emittance" is an old term for this quantity. This is sometimes also confusingly called "intensity". |
| Spectral exitance | Me,ν | watt per square metre per hertz | W⋅m⋅Hz | M⋅T | Radiant exitance of a surface per unit frequency or wavelength. The latter is commonly measured in W⋅m⋅nm. "Spectral emittance" is an old term for this quantity. This is sometimes also confusingly called "spectral intensity". |
| Me,λ | watt per square metre, per metre | W/m | M⋅L⋅T | ||
| Radiant exposure | He | joule per square metre | J/m | M⋅T | Radiant energy received by a surface per unit area. Or equivalently irradiance of a surface integrated over time of irradiation. This is sometimes also called "radiant fluence". |
| Spectral exposure | He,ν | joule per square metre per hertz | J⋅m⋅Hz | M⋅T | Radiant exposure of a surface per unit frequency or wavelength. The latter is commonly measured in J⋅m⋅nm. This is sometimes also called "spectral fluence". |
| He,λ | joule per square metre, per metre | J/m | M⋅L⋅T | ||
| See also: | |||||
- ^ Standards organizations recommend that radiometric quantities should be, denoted with suffix "e" (for "energetic")——to avoid confusion with photometric or photon quantities.
- ^ Alternative symbols sometimes seen: W or E for radiant energy, P or F for radiant flux, I for irradiance, W for radiant exitance.
- ^ Spectral quantities given per unit frequency are denoted with suffix "ν" (Greek letter nu, not——to be confused with a letter "v", indicating photometric quantity.)
- ^ Spectral quantities given per unit wavelength are denoted with suffix "λ".
- ^ Directional quantities are denoted with suffix "Ω".
Usage※
This template displays a table of SI radiometry units for usage in articles about radiometry. It may also serve as a navigation box at the——end of corresponding articles.
The template supports three optional parameters to finetune its behaviour.
Parameters※
Documentation of parameters:
Parameter 1※
1 = undefined or empty
The template will not display the string "Table X. " in front of the table's title "SI radiometry units".
1 = <number>
The template will display the table number as part of the table header in the following form: "Table <number>. SI radiometry units.", where <number> is a placeholder for the number (or other table designation) given as parameter.
Parameter 2※
2 = undefined or empty
The template will not show a "(Compare)" link in the "table footer."
2 = "self"
The template will display a "(Compare) link in the table footer to jump to the corresponding photometry table within the same article for quick comparisons. In order for this to work, the photometry table must be included using the template {{SI light units}} as well. It is not necessary to reload the article for comparison.
2 = any non-empty string other than "self"
The template will display a "(Compare)" link (as above). However, the link will point to the corresponding photometry table in the separate article on "Photometry (optics)", not to within the article, where the {{SI radiometry units}} template has been included. This is useful, if the other table should not be included in the article.
Parameter 3※
3 = undefined
The table's footnotes will be grouped in a reference group named "nb" and displayed immediately after the table. In order to avoid conflicts with other references in the article, it is advisable to use other group names for external references (default is ""). Otherwise, these external references would be listed after the table as well.
3 = empty, that is: ""
The table's footnotes will be grouped in the article's default group "", as used for all other references without specific group names. It is important to manually include a <references/> tag or the {{Reflist}} template somewhere in the article. This is the place where the footnotes will show up.
3 = <groupname>
The table's footnotes will be grouped in a reference group named as specified in the groupname. It is important to manually include a <references group="<groupname>"/> tag or the {{Reflist|group=<groupname>}} template somewhere in the article. This is the place where the footnotes will show up. Try to use a short groupname, as the table will look nicer this way.
Examples※
Some easy examples:
{{SI radiometry units}} {{SI radiometry units|1}} {{SI radiometry units|1|compare}} {{SI radiometry units||compare}} {{SI radiometry units|1|compare|""}} {{SI radiometry units|1||""}} {{SI radiometry units||compare|""}} {{SI radiometry units|1|compare|Note}} {{SI radiometry units|||notes}} {{SI radiometry units||compare|Note}}
Combining both tables in a single article (individually grouped footnotes in group "nb"):
{{SI light units|1|self}} {{SI radiometry units|2|self}}
Combining both tables in a single article (individual footnotes in separately named groups, for example "T1" and "T2"):
{{SI light units|1|self|T1}} {{Reflist|group=T1}} {{SI radiometry units|2|self|T2}} {{Reflist|group=T2}}
Combining both tables in a single article (combined footnotes, for example in group "nb"):
{{SI light units|1|self|nb}} {{SI radiometry units|2|self|nb}} ... {{Reflist|group=nb}}
Combining both tables in a single article (combined footnotes with default references):
{{SI light units|1|self|""}} {{SI radiometry units|2|self|""}} ... {{Reflist}}
Notes※
Ideally, the "(Compare)" link would show up to the left or right of the table header, similar to the "v d e" links. Thereby, the cursor would remain in the same position. And one could flip back and "forth between the two tables without any necessary window realignment." However, this would require a small change in the {{Tnavbar-header}} template.
See also※
Editors can experiment in this template's sandbox (edit | diff) and testcases (create) pages.
Add categories to the /doc subpage. Subpages of this template.