Neon signs are often used to advertise for hotels, bars and entertainment venues.

Neon signs are luminous-tube signs that contain neon or other inert gases at a low pressure. Applying a high voltage (usually a few thousand volts) makes the gas glow brightly. They are produced by the craft of bending glass tubing into shapes. Glass in the common sense refers to a Hard, Brittle, transparent Solid, such as that used for Windows many A worker skilled in this craft is known as a glass bender, neon or tube bender.

History

The neon sign is an evolution of the earlier Geissler tube (also called a Crookes tube), which is a glass tube for demonstrating the principles of electrical discharge. The Geissler tube is a glass tube for demonstrating the principles of electrical Glow discharge. Sir William Crookes, OM, FRS (17 June 1832 – 4 April 1919 was an English Chemist and Physicist. Neon signs are used for many purposes.

At the 1893 World's Fair, the World Columbian Exposition in Chicago, Illinois, Nikola Tesla's neon lamp signs were displayed. Year 1893 ( MDCCCXCIII) was a Common year starting on Sunday (link will display the full calendar of the Gregorian calendar (or a Common Expo (short for "exposition" and also known as World Fair and World's Fair) is the name given to various large public exhibitions held since the The World's Columbian Exposition (also called The Chicago World's Fair) a World's Fair, was held in Chicago in 1893 to celebrate the 400th anniversary Chicago (ʃɪˈkɑːgoʊ is the largest City by population in the state of Illinois and the American Midwest of the United States. The State of Illinois ( roughly ill-i-NOY is a state of the United States of America, the 21st to be admitted to the Union. There have already been discussions about Tesla's ethnicity on the talk page A neon lamp is a Gas discharge Lamp containing primarily Neon gas at low Pressure. The development of neon signs is credited to Georges Claude and the first public display of a neon sign was of two 38-foot long tubes in December of 1910 at the Paris Expo. The French Engineer, Chemist, and Inventor Georges Claude ( September 24, 1870 &ndash May 23, 1960 The first commercial sign was sold by Jaques Fonseque, Claude’s associate, in 1912 to a Paris barber. A barber (from the Latin barba, " Beard " is someone whose occupation is to cut any type of hair give shaves, and trim

Manufacturing process

Lead glass tubing in external diameters ranging from about 8 to 15 mm is most commonly used. Glass consists of a network former typically Silica (SiO2 and network modifiers including alkali fluxes such as Potassium oxide or Sodium The tube is heated in sections using several types of burners that are selected according to the amount of glass to be heated for each bend. These burners include ribbon, cannon, or crossfires, as well as a variety of torches that run on a simple combination of natural gas (butane or propane work better, however natural gas is cheapest) and air. Originally a torch was a portable source of Fire used as a source of light usually a rod-shaped piece of wood with a rag soaked in pitch and/or some other

A section of the glass is heated until it is malleable; then it is bent into shape and aligned to a pattern containing the graphics or lettering that the final product will ultimately conform to.

An electrode is melted (or welded) to each end of the tube as it is finished. An electrode is an Electrical conductor used to make contact with a nonmetallic part of a circuit (e Welding is a fabrication process that joins materials usually Metals or Thermoplastics by causing coalescence. The electrodes are also lead glass and contain a small metal shell with two wires protruding through the glass to which the sign wiring will later be attached. All welds and seals must be perfectly leak-proof before proceeding further.

The tube is attached to a manifold which is itself attached to a high-quality vacuum pump. This vacuum means "absence of matter" or "an empty area or space" for the cleaning appliance see Vacuum cleaner. The tube is then evacuated of air until it reaches near-vacuum. During evacuation, a high current is forced through the tube via the wires protruding from each electrode (in a process known as "bombarding"). Electric current is the flow (movement of Electric charge. The SI unit of electric current is the Ampere. The current depends on the specific electrodes used and the diameter of the tube, but is typically in the 500mA to 1000mA range, at an applied voltage usually between 15,000 to 25,000V. The bombarding transformer acts as an adjustable constant current source, and the voltage produced depends on the length and pressure of the tube. Typically the operator will maintain the pressure as high as the bombarder will allow to ensure maximum power dissipation and heating. This very high power dissipation in the tube heats the glass to a temperature of several hundred degrees Celsius, and any dirt and impurities within are drawn off in the gasified form by the vacuum pump. The current also heats the electrode metal to over 600 degrees Celsius, which activates a special coating that scavenges unwanted contaminants in the tube and reduces the work function of the electrode for cathodic emission. In Solid state physics, the work function is the minimum Energy (usually measured in Electron volts needed to remove an Electron from a solid When completed properly, this process results in a very clean interior at a high vacuum.

While still attached to the manifold, the tube is allowed to cool while pumping down to the lowest pressure the system can achieve. It is then filled to a pressure of a few torr with one of the noble gases, or a mixture of them, and sometimes a small amount of mercury. The torr (symbol Torr) is a non- SI unit of Pressure defined as 1/760 of an atmosphere. History Noble gas is translated from the German noun de ''Edelgas'' first used in 1898 by Hugo Erdmann to indicate their extremely low level of reactivity The required pressure depends on the gas used and the diameter of the tube, with optimal values ranging from 6 torr (for a long 20mm tube filled with argon/mercury) to 27 torr (for a short 8mm diameter tube filled with pure neon). Neon or argon are the most common gases used; krypton, xenon, and helium are used by artists for special purposes but are not used alone in normal signs. Neon (ˈniːɒn is the Chemical element that has the symbol Ne and Atomic number 10 This article pertains to the chemical element For other uses see Argon (disambiguation. Krypton (ˈkrɪptən or /ˈkrɪptɒn/ from kryptos "hidden" is a Chemical element with the symbol Kr and Atomic number 36 Xenon (ˈzɛnɒn or) is a Chemical element represented by the symbol Xe. Helium ( He) is a colorless odorless tasteless non-toxic Inert Monatomic Chemical A premixed combination of argon and helium is often used in lieu of pure argon when a tube is to be installed in a cold climate, since the helium increases voltage drop (and thus power dissipation), warming the tube to operating temperature faster. Neon glows bright red or reddish orange when lit. When argon or argon/helium is used, a tiny droplet of mercury is added. Mercury (ˈmɜrkjʊri also called quicksilver or hydrargyrum, is a Chemical element with the symbol Hg ( Latinized hydrargyrum Argon by itself is very dim pale lavender when lit, but the droplet of mercury fills the tube with mercury vapor when sealed, which then emits ultraviolet light upon electrification. Ultraviolet ( UV) light is Electromagnetic radiation with a Wavelength shorter than that of Visible light, but longer than X-rays This ultraviolet emission allows finished argon/mercury tubes to glow with a variety of bright colors when the tube has been coated on the interior with ultraviolet-sensitive phosphors after being bent into shape. A phosphor is a substance that exhibits the phenomenon of Phosphorescence (sustained glowing after exposure to energized particles such as Electrons Plain argon/mercury fill in clear glass is used for a bright but pale blue (or bluish white) color often seen in signs where cost is a major factor.

The finished glass pieces are illuminated by either a transformer or a switching power supply running at voltages ranging between 3,000 and 15,000 volts and currents between 20 and 60 mA. A transformer is a device that transfers Electrical energy from one circuit to another through inductively coupled Electrical conductors A switched-mode power supply, switching-mode power supply or SMPS, is an electronic Power supply unit (PSU that incorporates a switching regulator These power supplies operate as constant-current sources (a high voltage supply with a very high internal impedance), since the tube has a negative characteristic electrical impedance. Electrical impedance, or simply impedance, describes a measure of opposition to a sinusoidal Alternating current (AC The most common current rating is 30mA for general use, with 60mA used for high-brightness applications like channel letters or architectural lighting. 120mA sources are occasionally seen in illuminating applications, but are uncommon since special electrodes are required to withstand the current, and an accidental shock from a 120mA transformer is much more likely to be fatal than from the lower current supplies. Neon signs are a type of cold cathode lighting. A cold cathode is an element used within some Nixie tubes Gas discharge lamps Gas filled tubes and Vacuum tubes Cold cathodes do not Lighting includes both artificial Light sources such as lamps and natural illumination of interiors from Daylight.

Applications

The light-emitting tubes form colored lines with which a text can be written or a picture drawn, including various decorations, especially in advertising and commercial signage. Light, or visible light, is Electromagnetic radiation of a Wavelength that is visible to the Human eye (about 400–700 Advertising is a form of Communication that typically attempts to persuade potential Customers to Purchase or to consume more of a particular Brand Commercial signage identifies a business or similar entity assists in Wayfinding and attracts customers By programming sequences of switching parts on and off, there are many possibilities for dynamic light patterns that form animated images. The bouncing ball animation (below consists of these 6 frames

Images

Neon gas. This is the most commonly used of the noble gases.	Argon (with mercury). The second most common after neon.	Helium.	Krypton.
Xenon.	Neon used for commercial signage		Texas Music
A swinging neon sign in front of a children's clothing store has been a local landmark for over 50 years in North Burnaby, British Columbia

See also

• 1911 in science
• Neon
• Neon lamp
• Neon message board
• Timeline of lighting technology
• noble gases

External links

• A huge photo-collection of Swedish neon signs
• The history of neon signs