d = distance from light source (m)
E 1 d 1 2 = E 2 d 2 2 = constant (2)
(2) can be modified to
E 1 / E 2 = d 2 2 / d 1 2 (2b)
The illumination intensity from lamp with luminance 10000 lumens at distance 2 m can be calculated with (1) as
E 1 = (10000 lumens) / (2 m) 2
= 2500 lux
The illumination intensity at distance 5 m can be calculated by modifying (2b) to
E 2 = E 1 d 1 2 / d 2 2
= (2500 lux) (2 m) 2 / (5 m) 2
= 400 lux
E = Φ / d 2 cos θ (3)
θ = angle between light source vertical line and sight line
The SI-system, unit converters, physical constants, drawing scales and more.
Mathematical rules and laws - numbers, areas, volumes, exponents, trigonometric functions and more.
Solar radiation absorbed by various materials.
The electromagnetic spectrum with wavelengths and frequencies.
Heat contributed by lights may have major impact on air-condition systems.
Working activities and light levels - required illuminance.
Lights vs. power installations in common types of buildings and rooms.
Light sources and their color irradiation in degrees Kelvin.
The visible light produced by light sources.
Light reflecting factor materials.
Some common fluids and their refractive index.
Doubling of the distance from a noise source reduces the sound pressure level with 6 decibel.
Add standard and customized parametric components - like flange beams, lumbers, piping, stairs and more - to your Sketchup model with the Engineering ToolBox - SketchUp Extension - enabled for use with the amazing, fun and free SketchUp Make and SketchUp Pro . Add the Engineering ToolBox extension to your SketchUp from the Sketchup Extension Warehouse!
We don't collect information from our users. Only emails and answers are saved in our archive. Cookies are only used in the browser to improve user experience.
Some of our calculators and applications let you save application data to your local computer. These applications will - due to browser restrictions - send data between your browser and our server. We don't save this data.