This page documents an OPTIMADE Unit Definition. See https://schemas.optimade.org/ for more information.
ID: https://schemas.optimade.org/defs/v1.2/units/si/1979/named/lux
Definition name: lux
Unit name: lux
Latin symbol: lx
Display symbol: lx
Description: A derived SI unit for illuminance equal to cd⋅sr⋅m⁻² in the 1979 SI units.
"The lux is the illuminance of a surface that receives a uniformly distributed luminous flux of one lumen per square meter." [9th CGPM meeting in 1946]
The lux was defined at the 9th CGPM meeting in 1946, and implicitly redefined via the redefinition of the second at the 13th CGPM Meeting in 1967, resolution 1 and the redefinition of the candela at the 16th CGPM Meeting in 1979, resolution 3.
Resources:
JSON definition:
{
"$id": "https://schemas.optimade.org/defs/v1.2/units/si/1979/named/lux",
"$schema": "https://schemas.optimade.org/meta/v1.2/optimade/physical_unit_definition.json",
"title": "lux",
"symbol": "lx",
"display-symbol": "lx",
"description": "A derived SI unit for illuminance equal to cd\u22c5sr\u22c5m\u207b\u00b2 in the 1979 SI units.\n\n\"The lux is the illuminance of a surface that receives a uniformly distributed luminous flux of one lumen per square meter.\" [9th CGPM meeting in 1946]\n\nThe lux was defined at the 9th CGPM meeting in 1946, and implicitly redefined via the redefinition of the second at the 13th CGPM Meeting in 1967, resolution 1 and the redefinition of the candela at the 16th CGPM Meeting in 1979, resolution 3.",
"resources": [
{
"relation": "Definition and establishment of the SI unit system at the 11th CGPM meeting (1960), resolution 12.",
"resource-id": "https://www.bipm.org/en/committees/cg/cgpm/11-1960/resolution-12"
},
{
"relation": "Redefinition of the candela at the 16th CGPM Meeting in 1979, resolution 3.",
"resource-id": "https://www.bipm.org/en/committees/cg/cgpm/16-1979/resolution-3"
},
{
"relation": "Redefinition of the second in the 13th CGPM Meeting (1967), resolution 1",
"resource-id": "https://www.bipm.org/en/committees/cg/cgpm/13-1967/resolution-1"
},
{
"relation": "Wikipedia article describing the unit",
"resource-id": "https://en.wikipedia.org/wiki/Lux"
}
],
"defining-relation": {
"base-units": [
{
"symbol": "cd",
"id": "https://schemas.optimade.org/defs/v1.2/units/si/1979/base/candela"
},
{
"symbol": "sr",
"id": "https://schemas.optimade.org/defs/v1.2/units/si/1960/supplementary/steradian"
},
{
"symbol": "m",
"id": "https://schemas.optimade.org/defs/v1.2/units/si/1960/base/metre"
}
],
"base-units-expression": "cd*m^-2*sr"
},
"standard": {
"name": "si",
"year": 1979,
"category": "named",
"symbol": "lx"
},
"x-optimade-definition": {
"label": "lux_si_1979_named",
"kind": "unit",
"format": "1.2",
"version": "1.2.0",
"name": "lux"
}
}