What is tanning? A beautifully bronzed skin is an ideal for many people. A tan radiates wellbeing and health. Only a few are happy to go through life looking pale all year round. Moreover, the sun has a positive effect on people. They feel fitter, happier and possibly also healthier. In many countries, the time that real sun can be enjoyed is limited and unpredictable; sunbathing using tanning equipment is a good alternative. However, tanning is only beneficial in moderation. The rays from UV tubes are no different to those from the sun. Both contain visible and invisible light. The solar spectrum, or optical radiation, consists of visible light (the seven colours of the rainbow) and invisible ultraviolet and infrared. In a schematic diagram this can be conveyed by plotting the rays’ wavelength on a horizontal axis.
ELECTROMAGNETIC RADIATION OPTICAL RADIATION X-rays
UltraViolet
Visible
InfraRed
Microwave, Radar, TV, Radio
Here, visible light is positioned in the middle of the optical radiation, the infrared on the right (with long wavelengths) and the ultraviolet on the left (with short wavelengths). Infrared is thermal radiation and is used in many areas such as electric radiators, infrared cabins and microwave ovens. Ultraviolet can be subdivided into UVA, UVB and UVC. The first two play a role in the tanning of the skin. The sun’s UVC rays do not reach the earth’s surface because these rays are fully absorbed by the ozone layer. UVC is created artificially, e.g. to kill bacteria in swimming pools and in food products. UVC radiation is not used in sunbeds. UVB is responsible for the production of pigment cells and the previtamin D3, which is converted to the essential vitamin D in other organs afterwards. Vitamin D is vital for building up the
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bone structure, it also has a positive effect on the metabolism and it aids the lowering of the blood pressure. The disadvantage of UVB is that it causes sunburn (skin erythema). Even exceeding the correct dose by a fraction will lead to sunburn. UVA colours the pigment cells brown and is less critical in erythema, but higher doses are needed to encourage tanning of the skin. More than UVB, UVA stimulates the skin’s ageing process. As you can see, UV radiation is not a clear-cut
case of good and bad. It comes down to choosing the correct ratios UVA/UVB and applying it in moderation. That is why your Hapro sunbed is equipped with the most advanced tubes available. In order to direct the tubes’ radiation on to the body as efficiently as possible, reflectors are placed behind the tubes. There are tubes with built-in reflectors, the so-called reflector tubes; these are mainly used in the more expensive