What is illuminance?
Illuminance describes luminous flux incident on a unit area. It is a fundamental quantity for workplaces, interiors and outdoor areas.
Definition
Illuminance E is the surface density of luminous flux incident on a surface. Its unit is the lux (lx), equal to one lumen per square metre. The result depends on the measurement plane, luminaire distribution, distance and obstructions.
Good measurement practice
The meter should be positioned in the defined plane without shading its sensor. Directional response, spectral matching and current calibration matter. The L22 laboratory performs light measurements and confirms the accreditation status of a method before accepting an order.
Frequently asked questions
What is the unit of illuminance?
Lux (lx), or lumen per square metre.
What instrument measures illuminance?
A luxmeter, with its measurement head placed in a defined plane.