The structure of metal halide lamps

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Metal iodides are required to correct the spectral characteristics of the arc discharge, thanks to them, the quality of light radiation is significantly improved. They also prevent the settling of volatile tungsten on the inner walls of the bulb. During operation of metal halide lamps, a reaction of tungsten vapors and metal halides occurs. As a result of this reaction, tungsten iodide (a gaseous mixture) is formed, evaporating from the electrodes. After turning off the lighting device, tungsten settles back on the electrodes.

Metal halide lamps mainly consist of the following components:
Discharge tube (burner) - which is the basis of the MGL. The burner is most often made of quartz glass, there are also options made of special ceramics. Ceramic burners have higher heat resistance. The burner with electrodes is placed in the outer flask.
The outer flask acts as a light filter. It is made of australia mobile database glass. Borosilicate flasks have high thermal and mechanical resistance. The flask reduces heat loss from the burner, providing it with a normal thermal regime.
Base.
It is impossible to start the MGL without ballast, electromagnetic or electronic ballasts (PRA) are used as ballasts. Using an electronic PRA provides an even light when lighting the bulbs, significantly reducing currents (working and starting), and also increasing the service life of the lighting device.

Operating principle
The luminous body of the MGL is the plasma of the arc discharge flowing in the burner between the electrodes.

The discharge tube is filled with inert gases and halogen compounds, which in a cold state condense on its walls in the form of a very thin film. As the temperature of the arc discharge increases, the halides begin to evaporate and decompose into ions. After which the already ionized atoms are irritated and they create optical radiation.

The inert gas acts as a buffer, allowing electric current to flow through the burner even at low temperatures. As the burner heats up, mercury and radiating additives evaporate, thereby changing the emission spectrum, luminous flux, and electrical resistance of the MGL.