Glossary: Light, daylight, lighting, luminance, ballast, luminous flow, light bulb, strip lighting

An ideal lighting system should comply with DIN standard 67505 on the distribution, quantity and quality of light.
B2M products are the perfect answer to these criteria.

A device to stabilise the electric discharge required for the operation of discharge lamps. Electronic ballast avoids a strobe effect (flicker) when neon tubes are lit.

Illuminance is a physical value measured in lux. It corresponds to the quotient of luminous flow received by an element via its surface. It is, therefore, the quantity of light emitted in one second on a given surface.

Luminous flux is the quantity of light emitted in one second by a lighting source. It is expressed in lumens. This value is purely indicative because the calculation must be based on a surface situated at a given distance in order to define the actual characteristics of a source of light..

Light is an electromagnetic wave, which means that it is a ray spreading in space. The ray of light will meet a number of obstacles. When its path is obstructed in this way, the light will be reflected and the object will become visible.

A light source is defined in terms of the colours that it can reflect (colour index), the colour temperature (which defines its strength) and the illuminance.

Daylight is a light that is almost identical to external light. Its main feature is its excellent colour index (> 95%), making it possible to distinguish the differences in colours. It therefore avoids eyestrain and makes the workplace more pleasant.

Moreover, daylight tubes do not produce dazzle. The colour temperature of daylight is high (between 5,000 and 6,000 °K). This means that it is a cold light, bluish in colour.

It is measured at one point on a surface and in a given direction. It is expressed in candela per sq. metre. Luminance, also known as brilliance, determines the luminous appearance of a source or surface.

The colour index determines the ability of a light source to reproduce the natural colours of the objects being observed. The nearer the index is to 100, the more the perceived colours will be close to the natural colours.

In many professions, it is vital to be able to distinguish clearly between colours and hues. This is why it is advisable to work under a daylight-type light which provides a high colour index and limits eyestrain.

Colour temperatures are measured in degrees Kelvin (°K). This is merely one way of expressing the proportion between the various colours in a light. A light with a high colour temperature will include the largest possible number of colours whereas a so-called "warm" light (i.e. with a low colour temperature) will emit only in red tones.