On the package of many lighting manufacturers specify lamp characterizing parameter called color temperature. Because it is not sufficiently clear for a certain category of users - need to understand that it is and what is measured.
In certain situations, this indicator plays a crucial role when choosing the right radiator. All this fully applies to the modern LED light bulb.
What is the rate
Characterizing a light source color temperature is a measure of what length of an electromagnetic wave radiating elements. For its quantitative assessment experts was introduced a unit of measurement corresponding to the rank of the English physicist U.Tompsona (Kelvin or simply "K").
Able to evaluate sources of illumination in this parameter due to the fact that the human eye allows us to distinguish waves emitted by them in a rather wide range of temperatures.
Note: For the body of an ordinary person, this figure is in the range from 800 to 25000K.
The most suitable and comfortable to the human eye range of the spectrum is considered to be as close as possible to daylight.
The units of measure the color temperature it is rated as 4500-5200K (see photo below).
LED light sources
In the semiconductor light sources (LEDs) of the visible spectrum formation takes place in special coating called a phosphor. Electrons incident on it from the p-n junction diode, emboss secondary energy carriers (photons), which act on the human eye.
Existing LED devices in the spectrum of light emitted by them are divided into the following three groups:
- Emitters "warm" white light (up to 3500K).
- Diodes, forming a neutral color (3500K - 5200K).
- Finally, devices that emit "cool" white shade (above 5200K).
Conventionally, all these parameters are summarized in a single table below.
The physical essence
From a physical point of view, the temperature indicator shows the portion of the spectrum emitted from a hot body. According to the accepted rules it is a relative value and is measured in comparison with the blackbody radiation.
That is, the color temperature of any lamp is a glow body hue filament or other source of hot until a certain condition.
In accordance with this provision, the LED lamps are capable of forming three-gradation of the color spectrum:
- C yellow or "warm" shade (to 3200K).
- Pure white or natural color (4000-5500K).
- And finally, the white-blue range (above 5500).
With increasing heating temperature of the body length of a radiator formed by them wave decreases (see photos hereinafter).
There are LED light sources with a color indicator above 9000K, but to illuminate the objects around us they can not be used. Explained by the fact that all things visible to the eye, thanks to reflected light from them. With decreasing wavelength (increasing frequency oscillations) respectively and - the color temperature of its ability to perceive such light is significantly reduced.
As an example, usually is powerful torch, which change this figure can be arbitrarily. If you set it to 18000K around, he noticed a beam of light at the user's legs will be very difficult.