What is the working principle of metal halide lamp?

Metal halide lamp, also known as metal halide lamp, is a lamp made of metal halide. It has the characteristics of high luminous efficiency, long service life, good color rendering and stable performance. Metal halide reacts with electrode, glass and halide at high temperature, thus emitting characteristic spectral lines. Metal halide lamps and led lamps have their own advantages and disadvantages. They are different in light source type, redundant energy consumption form and vibration resistance. Different lights can be used according to the occasion. Let's take a look at the working principle of metal halide lamps! 1. What is a metal halide lamp?

Metal halide lamp, referred to as metal halide lamp for short, is a kind of discharge lamp driven by AC power supply, which produces arc discharge in the mixed vapor of mercury and rare metal halide. Metal halide lamp is the third generation light source made by adding various metal halides on the basis of high-pressure mercury lamp. Metal halide lamps mainly include timely metal halide lamps and ceramic metal halide lamps, which have the characteristics of high luminous efficiency (65 ~ 140 lm/w), long service life (5000 ~ 20000 h), good color rendering (Ra65 ~ 95), compact structure and stable performance.

Second, what is the working principle of metal halide lamp?

The arc tube of metal halide lamp is filled with mercury, inert gas and more than one metal halide. Metal halide, electrode, glass and halide will react chemically at high temperature.

When the metal halide lamp works, mercury evaporates, and the vapor pressure of mercury in the arc tube reaches several atmospheres. Halides also evaporate from the tube wall and diffuse into the high temperature arc column for decomposition. Metal atoms are excited by ionization, which radiates characteristic spectral lines, thus emitting light.

When metal ions diffuse back to the tube wall, they meet halogen atoms in the cold zone near the tube wall and recombine to form halide molecules. This cycle continuously supplies metal vapor to the arc.

The metal halide lamp cannot be reliably started only by the action of the trigger electrode. Bimetal starter, leakage transformer with high starting voltage and electronic trigger are generally used. The lighting of metal halide lamps also needs a current limiter (i.e. ballast), whose working current is greater than that of high-pressure mercury lamps with the same power.

3. Which is better, metal halide lamp or led lamp?

Metal halide lamps and led lamps have their own advantages and disadvantages. Led lamps are energy-saving, long-lived, sensitive and have many choices of primary colors. Metal halide lamps consume electricity and have a relatively short service life, but they have heavy sensitivity and single color, so they can be selected according to the application situation. The difference between metal halide lamps and led lamps is mainly reflected in the following aspects:

1, the difference of light source types

Metal halide lamps are thermal light sources; LED lamp is a cold light source.

The energy of LED is conserved, and the excess energy is not only converted into visible light, but also dissipated in other ways.

2, the difference between the form of excess energy dissipation

Metal halide lamps dissipate excess energy through infrared rays and ultraviolet rays, but infrared rays and ultraviolet rays will affect product quality and human physiology.

The LED lamp generates heat through the light source device, consumes redundant energy, and the heat conduction is easy to control.

3. Difference of lamp shell temperature

The shell temperature of metal halide lamp is very high, which can exceed 130 degrees.

The shell temperature of LED lamp is extremely low, generally below 75 degrees. The decrease of LED shell temperature can greatly increase the safety and life of cables, wires and supporting electrical appliances.

4, the difference of vibration resistance

The filament and bulb of metal halide lamp are easy to be damaged and have poor vibration resistance.

The light source of LED lamp is an electronic component, which has vibration resistance. LED lamps have incomparable advantages in anti-vibration.

5. Difference of light distribution performance

The light distribution performance of metal halide lamps is difficult, the waste is large, the light spot is uneven, a large reflector is needed, and the lamps are bulky.

LED lamp lines are easy to control, and uniform light distribution of multiple light spots can be realized in the same volume. The convenient light distribution of LED can greatly save the waste of light distribution of lamps and improve the system light efficiency of lamps and lanterns.

6, the difference between resistance to grid voltage interference

Metal halide lamp: the lamp power changes with the fluctuation of grid voltage, which is easy to overload.

LED lamp: stable constant current power supply, which can keep the power of light source unchanged when the grid voltage fluctuates. LED lamps can work normally during the fluctuation of grid voltage of 90 ~ 265V, which has no influence on the life of light sources and lamps.