How Do Neon Sign Work?

How do Neon Signs Work?

​The Science of the Glow
 

The Basics of Neon

Neon signs are made from glass tubes filled with a gas that emits light when electrified. While the term "neon" is often used generically, neon gas itself produces only a red-orange color. Other gases, such as argon, krypton, and xenon, are used to produce different colors. Each gas emits a distinct color when excited by electricity.

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The Role of Electricity

The process begins with a transformer that converts standard electrical voltage into a higher voltage suitable for the neon tubes. This high voltage is applied to electrodes at each end of the tube. When the gas inside the tube is energized by this electrical current, it becomes ionized. This means the gas particles gain enough energy to become electrically charged.

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The Glow

As the gas particles become ionized, electrons within the atoms get excited to higher energy levels. When these electrons return to their normal, lower energy state, they release energy in the form of light. This process is known as gas discharge. The color of the light depends on the type of gas used:

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• Neon: Red-Orange

• Argon (with a bit of mercury): Blue

• Krypton: White

• Xenon: Purple

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To create other colors, the inside of the glass tubes can be coated with phosphorescent powders. When the gas emits ultraviolet light, these powders fluoresce, producing a wide range of colors.

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Craftsmanship

Creating a neon sign involves skilled craftsmanship. Glass tubes are carefully heated and bent into shape by experienced artisans, often referred to as "glass benders" or "neon tube benders." Once shaped, the tubes are cleaned and filled with the appropriate gas before being sealed with electrodes at each end.

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The Significance of Pressure

The gas inside the neon tube is kept at low pressure, typically around 3-20 Torr (a unit of pressure). This low pressure allows the gas to ionize more easily when an electrical current is applied, ensuring a consistent and bright glow.

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Durability and Maintenance

Neon signs are known for their durability and longevity. With proper care, a well-made neon sign can last for decades. Maintenance typically involves checking the electrical connections and ensuring the tubes are intact and free from contaminants.