Tanning bed

A tanning bed is a device that emits ultraviolet radiation to give people a tan (make their skin darker).  Like the sun, a tanning bed can also cause a sunburn if the person stays in too long.  There are many kinds of tanning beds, but most look like the one in the photo.

History
Tanning beds became popular in Europe and America because of the work of Friedrich Wolff around 1979.  He patented his design and charged others to use his ideas. His company, "Wolff Systems" does not build the tanning beds, they research and design for the tanning lamp. Some of the early adopters of the Wolff technology include ETS, Inc., SCA, Sun Industries, Inc., Montego Bay, Sunal. Later, Friedrich sold Wolff Systems to his brother Jorg Wolff, who was the founder of Cosmedico, Ltd., another pioneer in the tanning industry.

Design
Tanning beds use a special fluorescent lamps (16 to 32 per tanning bed) that creates visible light and ultraviolet light.  Like all fluorescent lights, they use a ballast system to limit the electricity going to each lamp, which is most often 100 watts per lamp.  The tanning beds use a special acrylic, or clear shield over the lamps.  Most clear plastics will block ultraviolet, but this special type of plastic lets most of the ultraviolet light pass through.  Most tanning beds also have a cooling fan system, to cool the electronics inside the tanning bed and keep it from getting too hot.  All tanning beds have a timer, a device to limit the amount of time the person is exposed to the ultraviolet light.  After a few minutes, the timer makes the bed turn off.

Benefits and risks
Unlike the sun, tanning beds do not help the body produce vitamin D as their bulbs emit mostly UVA light. The human body needs UVB light to produce vitamin D. Both the sun and tanning beds can damage your skin if you stay exposed for too long.  Getting too much UV, or many sunburns can cause skin cancer, including melanoma, which can be deadly.  There is a lot of controversy due to the risks.  Most countries have many laws and rules that regulate tanning beds.

References

Category:Electromagnetic radiation
Category:Skin
Category:Ultraviolet radiation