Units of measure

The base unit in the International System of Units referring to luminous intensity, that is, the light concentration/ power emitted by a light source in a particular direction on a solid angle (steradian). This value is irrespective of the distance at which it is measured. Candelas are calculated from lumens according to the following formula: 1 lm/sr (lumen by steradian) = 1 cd. Usually the luminous intensity of dichroic bulbs is indicated in candela specifically because it is directed in a particular light cone.

Unit of measure for electrical frequency indicating how many times an event occurs within a second.

International System unit of measure for temperature; in lighting design it refers to the colour tone of the light emitted. The LEDs we use are generally warm white (average 2,700 K).

Unit of measure that corresponds to the photometric equivalent of a watt. It refers to the luminous lux (in other words the quantity of luminous energy emitted by a light source) visible by the human eye. In general, what relates the intensity with the lux (candela with lumen) is the angle of emission of light. To calculate the lumen/ candela conversion, you have to convert the radiation angle of the beam (supplied by the manufacturer in degrees) in a solid angle (unit of measure: steradians). Thus we can calculate, for instance, that a LED with an intensity of 2.4 cd and a diffusion angle of 120 ° will present a lux of about 7.5 lm.

Unit of measure for illuminance of the luminous ux (lumen) per unit area. In other words, it indicates the visible lux (lumen) per square metre at a particular distance. The greater the distance between the source and the surface, the lower the lux detected.

Derived unit of power in the International System of Units for the measurement of difference in potential; it usually refers to the voltage of the electrical system (230V, 110V, 12V, 24V) or to the supply voltage of the light sources.

Unit of measure of the International System of Units referring to electrical power (W = V * A) and so to actual consumption. For instance: a LED board with a voltage of 2.85 volts powered at 350 mA consumes about 1W.