Saturday, October 22, 2005

Is the Neon in Neon Signs Dangerous?

Neon and argon gas by themselves are not dangerous. They are inert gases that can be found in the air we breath every day.

How Do you Get the Different Neon Colors?

The initial color source is the inert gas, which emits a characteristic color when electricity is applied. The two most common gases are neon, which emits a fiery red, and a mixture of argon and minute particles of mercury, which emits a subdued blue. Clear glass allows you to see the characteristic colors emitted by the gas. Fluorescent powders may be painted or baked to the inside walls of the glass tubing and the source light is then converted into a multitude of shades such as pink, turquoise, and green. By altering the mixture of elements, subtle differences are possible. For example, white is available in a wide array of color temperatures from warm to cool.

Tubing is also produced in colored glass. Deep clear reds, blues, and greens for example produce the richly saturated colors referred to as Classic glass. Colored glass may also have a fluorescent coating, which can change both the quality and color of the light. The result is a whole range of neon colors ranging from white to purple.

How Does a Neon Tube Produce Light?

Electrical current bombard the inert gas atoms with electrons knocking neon's atoms out of their orbits. The electrons collide with other free electrons sending them back toward the atoms. As the electrons are absorbed into the atom, energy is given off as light.

The First Neon Sign

The concept behind neon signs was first conceived in 1675, when the French astronomer Jean Picard observed a faint glow in a mercury barometer tube. When the tube was shaken a glow called barometric light occurred, but the cause of the light (static electricity) was not then understood. When the principles of electricity were discovered, scientists moved forward towards the invention of various forms of lighting. By 1855, there was the geissler tube named after Heinrich Geissler, a German glassblower. Gas in the tube was placed under low pressure and electrical voltage was applied, the result was that the gas glowed. After electrical generators were invented, many people experimented with applying electric power to tubes of gas. The French engineer, chemist, and inventor Georges Claude, was the first to apply an electrical discharge to a sealed tube of neon gas (circa 1902) to create a lamp. The word neon comes from the Greek "neos," meaning "the new gas". Georges Claude displayed the first neon lamp to the public on December 11, 1910, in Paris. In 1923, Georges Claude and his French company Claude Neon, introduced neon gas signs to the United States, by selling two to a Packard car dealership in Los Angeles. Earle C. Anthony purchased the two signs reading "Packard" for $24,000. Neon lighting quickly became a popular fixture in outdoor advertising. Visible even in daylight, people would stop and stare at the first neon signs dubbed "liquid fire."