The Science Behind Neon Signs

FAQ, Neon Signs -

The Science Behind Neon Signs

Neon signs have only been in the United States for about 100 years.  They were first introduced when Packard Motor Car tycoon Earle C. Anthony commissioned two large neon signs from France, glowing with the Packard name.  These neon signs caused such a commotion that it was literally stopping traffic!  


A Brief History of Neon Lights

Neon signs are created using Neon (Ne), which is a gas, and other similar gases.  Neon gas was first discovered by a Scottish chemist named Sir William Ramsay and his colleague Morris W. Travers in 1898.  Neon was not Sir Ramsay’s first discovery. In 1894, Sir Ramsay and Lord Rayleigh discovered argon gas. And in 1895, Sir Ramsay encountered the first sample of helium.  Sir Ramsay knew without a doubt that there was an element somewhere between helium and argon that was missing. After many instances of trial and error, Sir Ramsay and Morris Travers decided to freeze a sample of argon with liquid air.  When the sample started emitting a gas, they collected that gas in a glass vacuum tube. Once the gas was trapped, they began running tests to learn the spectrum of the gas sample. One of the tests included applying a high voltage of electricity to the glass tube, which resulted in the discovery of neon gas and the creation of neon lights.

It would only be a few short years later that neon lights would make a show stopping appearance throughout France and Europe, with America not far behind.

While it was not he who discovered them, it was French Engineer George Claude who had introduced France, and the world, to the first ever neon lights.  During the Paris Motor Show in 1910, George Claude had adorned a building with 40-ft tall vacuum tubes filled with the red-orange glow of neon, dazzling the city of Paris.  After making their debut at the Paris Motor Show in 1910, it would be only two more years until businesses began using neon lights to advertise their establishments, with a Parisian barbershop leading the charge.

So, when did neon lights make it to the United States?  Earle C. Anthony of Packard Motors commissioned two neon signs in blue and orange for showrooms in Los Angeles and San Francisco from France.  Americans were so enthralled with the giant glowing lights it caused a disruption to the flow of traffic. By the mid-1900’s, neon signs began to take off in the U.S. 


How Does Neon Work?  

Neon gas (Ne) fills a vacuum tube which has electrodes on both ends.  The electrical current (about 15,000 volts) flows through the vacuum tube and ionizes the atoms of the gas.  This process allows electrons to escape the atoms, creating “free” electrons. Once the electrons become neutral, the color becomes visible, giving us that bright red-orange glow we’ve come to know so well.  The same process applies to the other gases used in neon signs as well.

The glass tubes used for neon lights typically come in either four or five foot tubes with varying diameters.  The glass tube contains a phosphorus powder and the gas. Attached to both ends of the tube are the electrodes where the electricity will be conducted.  The glass tubes can be bent to any shape. Many tube benders use patterns to ensure the highest quality designs. They are typically made in parts and then welded together at the end before being filled with the appropriate gas based on the intended color.


Is Neon (Ne) Really in Neon Lights?

Yes and no.  Contrary to the name “neon signs”, neon gas is only used in some colors.  Various other gases are used to create different colors for neon signs. Another common gas used in neon signs is argon.  Argon gives off a weaker light and emits a shade of blue. Often, a small bit of mercury is added to make the light a bit stronger.  While helium is rarer, it can be used to create pink-red lights. Another element/gas that can be used for neon signs is xenon. Xenon gives off a shade of lavender/light purple.  The primary place you’ll see xenon isn’t in neon lights, but rather, you’ll have likely seen it in strobe lights and flash photography. While krypton is used for more than just neon signs, it provides easy color manipulation due to the color it emits.  This element emits a white-yellow glow and when paired with a vacuum tube with colored glass, it is the color of the glass that will glow.

While neon, argon, helium, xenon and krypton can all be used to create those big, colorful signs, the two primary sources of gas used in neon signs are neon and argon.  Since argon produces a weaker light, it can be used to create a yellow, white and green in addition to the natural blue it emits. Color manipulation can also be achieved by pairing the gas with a colored vacuum tube.  For instance, with argon releasing a shade of blue, if we were to fill a yellow vacuum tube with argon, the resulting color would be green.


Environmental Impact of Neon Signs

Many worry that neon signs will have a negative impact on the environment.  They do use natural gases, after all. Thorough research has been conducted on these gases and it has been found that neon and argon gases are inert and non-toxic, meaning they are not dangerous.  However, some neon signs contain small amounts of mercury which can be harmful. When neon signs are disposed of properly, it greatly minimizes any negative impact. In addition, the power consumption of neon lights can be over 50 percent less than the amount of energy fluorescent lights use.  When taking energy consumption into account, neon lights are clearly a more sustainable option than fluorescent lights.

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