How altitude affects the performance of a Plasma TV?
July 13, 2007
How altitude affects the performance of a Plasma TV?
Plasma TV uses rare gases like xenon, neon and argon which are enclosed between two glass sheets. For the optimum performance of the plasma TV, there must be a balance between the pressure of these gases inside the plasma display panel and the atmospheric pressure. In other words, both the pressures should be more or less equal for optimum performance. However, when the altitude increases, say above, 2500 ft above sea level, the atmosphere becomes thinner, resulting in low atmospheric pressure. In such conditions, the gases inside a plasma TV tend to work hard to produce the display. During this process, a plasma TV usually produces more heat and a sort of buzzing noise when it is working.
Most of the plasma TVs are designed to work at sea levels or within 3000 ft ASL. However, if you happen to live in higher altitudes, say in a place over 5000 ft ASL, you should go for a plasma TV which is especially designed for such conditions.
It is fairly easy to find out whether your plasma TV struggles to cope up with low atmosphere outside. One way is to feel the heat emitted by your TV. Another way is much easier the buzzing noise can be heard when your TV works much harder. Nowadays, this problem is being eliminated as newer plasma TVs come with design and calibration suitable for higher altitudes
How does a Plasma TV work?
May 18, 2007
Both Plasma TV and the conventional CRT-type display use phosphors to produce the display. The screen of these display systems is made up of tiny spots known as pixels which have a phosphor coat on their back.
We can also compare a Plasma TV with a fluorescent lamp although on a superficial level. Not only they use the luminous properties of phosphors, they also use inert gases like argon, neon, xenon which in a plasma state, emit invisible, ultra-violet photons. In a fluorescent bulb, these emitted photons strike the phosphorous coating of the inner wall of the bulb resulting in a radiant glow, which fills our rooms.
However, a Plasma TV, which works on the same principle, has innumerable tiny fluorescent lamps, which are called pixels. Each Pixel, in its turn, has three tiny sub-pixels coated with red phosphor, green phosphor and blue phosphor. The pixels or cells are filled with rare gases like neon and xenon and the entire network of pixels is placed between two sheets of glass.
Two sets of electrodes address electrodes and display electrodes form two separate grids, one along the rear glass plate and another along the front glass plate. Once electric current is passed between the electrodes, it excites the noble gases to release the electrons thereby producing ions and free flowing electrons in the mixture. These charged particles rush towards electrically opposite charged electrodes, collide with each other and emit invisible, ultra violet photons. These photons react with the colored phosphors (RGB) in the sub-pixels and give visible light.
The overall shade of the pixel depends on the intensity of each sub-pixel which is proportionate with the level of electricity passing though it. To show a gamut colors, these three basic colors, RGB, are blended in different combinations by varying the intensity of each color. Plasma display Panels have a special feature, PCM (pulse code modulation) which modulates the electric pulse at a rapid rate and enable the production of more than 17 million colours.
