Welding helmet - AbsoluteAstronomy.com

Welding helmets are headgear

Headgear

Headgear, headwear or headdress is the name given to any element of clothing which is worn on one's head.Headgear serve a variety of purposes:...

used when performing certain types of welding

Welding

Welding is a fabrication or sculptural process that joins materials, usually metals or thermoplastics, by causing coalescence. This is often done by melting the workpieces and adding a filler material to form a pool of molten material that cools to become a strong joint, with pressure sometimes...

to protect the eyes, face and neck from flash burn, ultraviolet light, sparks

Spark (fire)

A spark is an incandescent particle. Such sparks may be produced by pyrotechnics, by metalworking or as a by-product of fires, especially when burning wood.-Pyrotechnics:...

, infrared light, and heat. Most commonly used with arc welding

Arc welding

Arc welding is a type of welding that uses a welding power supply to create an electric arc between an electrode and the base material to melt the metals at the welding point. They can use either direct or alternating current, and consumable or non-consumable electrodes...

processes such as shielded metal arc welding

Shielded metal arc welding

Shielded metal arc welding , also known as manual metal arc welding, flux shielded arc welding or informally as stick welding, is a manual arc welding process that uses a consumable electrode coated in flux to lay the weld...

, gas tungsten arc welding

Gas tungsten arc welding

Gas tungsten arc welding , also known as tungsten inert gas welding, is an arc welding process that uses a nonconsumable tungsten electrode to produce the weld...

, and gas metal arc welding

Gas metal arc welding

Gas metal arc welding , sometimes referred to by its subtypes metal inert gas welding or metal active gas welding, is a semi-automatic or automatic arc welding process in which a continuous and consumable wire electrode and a shielding gas are fed through a welding gun...

. Welding helmets are necessary to prevent arc eye, a painful condition where the cornea

Cornea

The cornea is the transparent front part of the eye that covers the iris, pupil, and anterior chamber. Together with the lens, the cornea refracts light, with the cornea accounting for approximately two-thirds of the eye's total optical power. In humans, the refractive power of the cornea is...

is inflamed. Welding helmets can also prevent retina

Retina

The vertebrate retina is a light-sensitive tissue lining the inner surface of the eye. The optics of the eye create an image of the visual world on the retina, which serves much the same function as the film in a camera. Light striking the retina initiates a cascade of chemical and electrical...

burns, which can lead to a loss of vision. Both conditions are caused by unprotected exposure to the highly-concentrated ultraviolet and infrared rays emitted by the welding arc. Ultraviolet emissions from the welding arc can also damage uncovered skin, causing a sunburn-like condition in a relatively short period of welding. The modern welding helmet used today, was first introduced in 1937 by Willson Products.

All welding helmets include a window covered with a filter called a lens shade, through which the welder can see to work. In most helmets, the window may be made of tinted glass, tinted plastic, or perhaps a variable-density filter made from a pair of polarized lenses. Recently helmets have been developed that use an electronic LCD shutter that darkens automatically when exposed to the bright welding arc so the welder

Welder

A welder is a tradesman who specializes in welding materials together. The materials to be joined can be metals or varieties of plastic or polymer...

can see to work under normal ambient light while wearing the helmet. With the development of electronic auto-darkening helmets, the welder no longer has to get ready to weld and then nod their head to lower the helmet over their face. However, these electronic auto-darkening helmets are significantly more expensive.

All welding helmets, are susceptible to damages such as cracks that can compromise the protection from ultraviolet and infrared rays. In addition to protecting the eyes, the helmet protects the face from hot metal sparks generated by the arc and from UV damage. When overhead welding a leather skull cap and shoulder cover are used to prevent head and shoulder burns.

In the United States, the industry standard for welding helmets is ANSI Z87.1 which specifies performance of a wide variety of eye protection devices. The standard requires that auto-darkening helmets provide full protection against both UV and IR even when they are not in the darkened state. The standard is voluntary, so prudent buyers should confirm that the helmet is ANSI Z87.1 compliant (indicated by appropriate labeling).

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