The peak of popularity of neon signs came in the 40-50s of the last century. However, they have not lost their relevance to this day, and always look very beautiful and impressive. But few people know that the first neon sign appeared in 1912, it was installed above the entrance to the Palais Coiffeur hairdressing salon in Paris. The first neon lamp was presented even earlier – in 1910. As you can easily guess from the name, neon gas is pumped inside these lamps. But have you ever wondered how neon lamps work and how luminous advertising signs are made?
Neon signs have been popular for over 100 years. Photo source: neon-show.ru
The history of neon lamps
The history of the neon lamp goes back to 1675, when the French astronomer Jean Picard saw a barely noticeable glow in the tube of a mercury barometer. At that time, no one knew about the existence of electricity. The mysterious glow was called “barometric glow”. Since then, scientists have long tried to figure out the nature of this phenomenon.
In the mid-19th century, German physicist Heinrich Geissler made a breakthrough in this field and created a lamp that became the predecessor of modern gas-discharge lamps. It can be said that from this moment the history of neon lamps began. Also, some kind of neon lamps were invented by Nikola Tesla in 1894. However, neon itself was discovered a little later – in 1989.
The first neon signs began to appear in Paris at the beginning of the 20th century. Photo source: thecinetourist.net
About 10 years later, the Frenchman Georges Claude decided to use neon in a sealed container. This is how the modern neon lamp was born, which was presented to the general public in 1910. According to legend, it was his friend Jean Fonseca who suggested that Georges Claude use neon lamps in advertising signs. As a result, five years later, a company producing advertising signs was founded – Claude Neon Lights, Inc.
Neon advertising signs became widespread in the first half of the 20th century, when entrepreneurs tried by any means to attract customers' attention to their products or their establishments. They became especially popular in the United States, where even small shops were often illuminated with neon.
This photo taken in Paris in 1925 shows how popular neon signs were in the 1920s. Source: thecinetourist.net
How a neon lamp works
Neon is an inert gas, meaning it does not react with other elements and is colorless and odorless. Therefore, it is impossible to see it or detect its presence in any way. By the way, this is a fairly rare gas that is used not only for signs, but also for making chips, which we have already discussed earlier.
When electricity flows through the glass tube of a neon lamp, it excites the electrons in the gas. They speed up and leave their orbits, throwing out positively charged ions. These free electrons fly through the environment and bump into a large number of neon atoms, causing them to ionize as well. The excess energy that is generated is carried away by particles of light, or photons. This is the glow we see.
Neon glows red. Photo source: jazzlight.ru
It should be said that neon glows red, but neon signs often come in different colors. This is usually achieved by tinting the glass of the lamp. But sometimes, to achieve a particular color, other gases are pumped into the lamps instead of neon. For example, argon produces violet light, helium glows pink, and xenon glows blue. The term “neon light” itself is usually used for any gas-discharge lamps, regardless of what gas is used in them.
Glass tubes for signs are bent by hand. Photo source: pro-r.ru
How neon signs are made
The production of a lamp begins with giving the glass tube the desired shape. For example, it can be made in the form of a letter, logo, etc. It should be said that the production of glass tubes is a rather complex task, since it is necessary to take into account such parameters as the diameter, on which the brightness of the light will depend, as well as the minimum allowable bending radius, the total length of the tube, the power of the transformer, etc.
To give a glass tube a particular shape, it is heated using gas burners. Bending is done manually, with the master focusing on a template. To ensure that the diameter does not change during the bending process, the end of the tube is connected to a blow-out hose and air is pumped through it. If the diameter changes, the light will be uneven or the lamp will not work properly at all. It should be noted that the length of the tube is no more than 3 meters. Therefore, several sections are used for large signs.
Glass tubes are heated using gas burners. Photo source: pro-r.ru
After the tube has been given the required shape, an electrode is melted onto each end. Then a process called “bombardment” is carried out. Air is pumped out of the tube, and then a small amount of dry air is pumped in so that the pressure reaches 0.5–1.0 mm Hg. After this, a transformer is connected to the electrodes and high voltage is applied. The glass is heated to a temperature of over 200 degrees, and the metal electrode to 760 degrees. This displaces any impurities.
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When the tube cools, air is pumped out of it and filled with gas. The technological hole is sealed. But the work does not end there. Next, the so-called “training” of the tube occurs. This is necessary so that the gas inside stabilizes and works properly. A transformer is connected to the tube and a more powerful current than its operating current is supplied. In this mode, the lamp operates from 15 minutes to several hours, depending on the type of gas that was pumped in. If the lamp is made well, it can last from 30 to 40 years.