How to assess the quality of lighting installations in the workplace

Lighting in the workplace is a key environmental factor for employees: we need to set up an appropriate work environment. Different levels of lighting are required for different types of work – close, accurate work such as soldering a control panel will require higher light levels than a waiting room.

Many laws and standards regulate lighting in the workplace. Units of measures are typically used by professionals to assess the quality of  lighting in the workplace.

Here is an overview:

NameDescriptionSymbolUnit
Luminous fluxThis is the amount of energy emitted by a source in the form of visible light in the entire space per unit time.FLumen lm
Light intensityAmount of radiated light emitted in a given point source direction.ICandela(Cd)
LuminanceLuminance is a photometric measure of the luminous intensity per unit area of light travelling in a given direction. It describes the amount of light that passes through or is emitted from a particular area, and falls within a given solid angle. Measures the light intensity collected in a direction and at a point of the light reflected from an illuminated surface. L’appareil de mesure s’appelle un luminancemètre.Lcd / m2(Candela per m2)

 

IlluminanceIilluminance is the total luminous flux incident on a surface, per unit area.The instrument is called a lux meter. This is an important unit of measur for the standards of comfort and safety.ELux (lx)
Luminous efficiencyThe luminous efficiency of a system depends not only on the source, but also on the accessoriesof the light fixture (reflectors, light distribution grid, transparent protection).Lm / WLumen / Watt
Color temperatureThe color temperature is used to determine the temperature (actual or “virtual”) of a light source, from its color.KKelvin
LifetimeThis feature is important when the cost of replacing the bulbs is expensive (if it is difficult to change the bulbs, for example in the case of high ceilings). Hr