TYPES OF LIGHT

led lights
A lamp is an energy converter. Although it can find other applications, its primary purpose is the transformation of electrical energy into electromagnetic radiation in the visible range. There are many ways to create light. The standard method of creating general lighting is to convert electrical energy into light.

Glow:

When heating solids or liquids, they emit visible radiation at temperatures above 1000 K; this phenomenon is called "incandescence".
It forms the basis of light production in filament lamps: an electric current passes through a thin tungsten wire, whose temperature reaches 2500 to 3200 K, depending on the type of lamp and its use.
This method is subject to a limit, described by Planck's Law for Emissivity of the Blackbody, according to which the spectral distribution of radiated energy increases with temperature. At around 3600 K and above, there is a significant gain in the emission of visible radiation, and the wavelength of the emission maximum moves in the visible range. This temperature is close to the melting point of tungsten, used for the filament, and the limiting temperature is therefore in practice around 2700 K because beyond this, the evaporation of the filament becomes excessive. These spectrum shifts have, among other things, the consequence that a large part of the radiation emitted is not restored in the form of light, but in the form of heat in the infrared zone.

Shock:

Electric shock is a technique used in modern lighting sources for commerce and industry, because of its better efficiency in the production of light. Some types of lamps combine electrical discharge and photoluminescence.


An electric current flowing through a gas causes excitation of atoms and molecules that emit radiation with a characteristic spectrum of the elements present. Two metals are usually used, sodium and mercury, because their characteristics make it possible to obtain radiation in the visible range. None of these two metals emitting a continuous spectrum, the discharge lamps have selective spectra. Their rendering of colors will never be identical to that of a continuous spectrum. Discharge lamps are often classified in high and low pressure, although these terms are relative and a high-pressure sodium lamp operates below one atmosphere.
to See more Click Here

Comments

Post a Comment

Popular posts from this blog

The main types of lamps

Image
Incandescent lamps: These lamps use a tungsten filament placed in an inert gas or in a vacuum inside a glass bulb. The inert gas eliminates the evaporation of the tungsten and reduces the blackening of the casing. There is a wide variety of lamp shapes whose appearance is primarily for decorative purposes. Incandescent lamps are still widely used for domestic lighting because of their low cost and compactness. However, for commercial and industrial lighting, their low efficiency makes them expensive to use, which is why gas discharge lamps are the most common choice. Thus, a 100W lamp has a typical efficiency of 14 lumens/watt, while a 36W fluorescent lamp provides 96 lumens/watt. Incandescent lamps whose flow can be easily varied by reducing the supply voltage are still used when the variation in light is an important feature of use. Tungsten filament is a compact light source that is easy to focus with reflectors or lenses. Incandescent lamps are very useful for l...
Read more

Lamp life

Image
Most lamps will need to be replaced several times during the life of the lighting system. Designers should, therefore, minimize the inconvenience that occasional maintenance and breakdowns can cause to occupants. The lamps are used in a wide range of applications. The average life is often a compromise between cost and performance. Thus, the lamp of a slide projector will have a lifespan of one hundred hours, because it is important for the quality of the image to have a maximum luminous flux. On the contrary, some street lighting lamps can be changed every two years, after some 8,000 hours of operation. In addition, the life of the lamps is affected by the operating conditions, so that there is no single value applicable to all cases. Similarly, the effective life of a lamp can be determined by different failure modes. A physical failure, such as a break in the filament or lamp, may be preceded by a decrease in the luminous flux or a change in its color appearance. The lif...
Read more