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/1967/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 1967 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, included in SI at the 11th CGPM meeting in 1960, resolution 12 and implicitly redefined via the redefinition of the second at the 13th CGPM Meeting in 1967, resolution 1.
Resources:
JSON definition:
{
"$id": "https://schemas.optimade.org/defs/v1.2/units/si/1967/named/lux",
"$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 1967 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, included in SI at the 11th CGPM meeting in 1960, resolution 12 and implicitly redefined via the redefinition of the second at the 13th CGPM Meeting in 1967, resolution 1.",
"resources": [
{
"relation": "Definition at the 9th CGPM meeting (1948)",
"resource-id": "https://www.bipm.org/en/committees/cg/cgpm/9-1948"
},
{
"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 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/1967/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": 1967,
"category": "named",
"symbol": "lx"
},
"x-optimade-definition": {
"label": "lux_si_1967_named",
"kind": "unit",
"format": "1.2",
"version": "1.2.0",
"name": "lux"
}
}