Why Neon Glow Lamp can be issued a different color?
Neon Glow Lamp are different from ordinary incandescent light. There is no filament inside the Neon Glow Lamp (only at the end of the electrode), and the thin lamp filled with inert gas (Neon Glow Lamp, argon, krypton or xenon). Once the high voltage (10 to 15 kV) is connected to the electrodes at both ends of the Neon Glow Lamp, a small amount of free electrons in the tube move to the anode under high voltage, while accelerating the impact of the inert gas molecules, Ionization, into a plasma state, while the ion in the electric field to accelerate the formation of the current through the lamp.
These ions continue to undergo a collision (ionization) and recombination process, will be issued with a specific atomic energy level transition corresponding to the various colors of glow. So this discharge is also called "glow discharge".
The color of the Neon Glow Lamp light is related to the type of gas filling in the tube: if the Neon Glow Lamp is filled in the lamp, it is a yellowish light in warm colors; if it is filled with argon, it is a cool blue and white light The The actual Neon Glow Lamp can emit a variety of tones in the light also the tubes of the inner wall coated with different materials for the phosphor. Different inert gases with different phosphors can make Neon Glow Lamp red, orange, yellow, green, blue, indigo, purple and other colors of light.