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INTENDED USE: Wolff System sunlamps are intended for use in sunlamp products for tanning of the human skin.

This 510(k) applies to more than one hundred and eighty individual devices that fall into a generic class of ultraviolet lamps that have the same basic technological features and exactly the same intended use. The ultraviolet sunlamps of this 510(k) are classified scientifically as low pressure, mercuryrare gas discharge devices. The general lamp construction and technological principle of operation of all of the devices of this 510(k) is the same as that of a common fluorescent lamp. The main differentiators for the various sunlamps of this 510(k) include: lamp length, lamp diameter, lamp wattage, spectral characteristics and private labeling thereof. The ultraviolet lamps named herein comprise a tubular glass envelope, the internal surface of which is coated with a fluorescent phosphor. To each end of the tube, a glass mount is sealed. The main purpose of the mount is to provide 1) for a means of hermetically sealing the internal atmosphere of the tube, 2) a means of supporting an electrode and a means of 3) electrically accessing the internal atmosphere of the device via electrically conducting lead-wires. Once assembled as described, the envelope is evacuated of air, the air is replaced by an inert gas at a pressure significantly lower than that of the normal atmosphere, and a drop of mercury is injected into the enclosed envelope. Finally, the envelope is sealed. In operation, the device, now called a "lamp", is connected to an electrical source typically in series with a ballast that provides for 1) ignition of a discharge through the inert-gas-mercury vapor mixture and 2) its subsequent stabilization and sustainment of the electrical behavior of the lamp. Once connected to the applied electric field, free electrons are accelerated through the mercury vapor wherein collisions take place with the mercury atoms. These collisions cause excitation of the electrons in the mercury (Hg) atom and the production of photons at various wavelengths. Certain of these photons travel to the bulb wall and excite the phosphor powder. The phosphor, in turn, emits radiation that is transmitted through the transparent glass envelope. The radiation that is emitted from a standard fluorescent general lighting lamp is primarily in the visible region of the spectrum (380nm-760nm). The radiation that is emitted from an ultraviolet sunlamp is primarily in the UV range of the electromagnetic spectrum (300nm-400nm). Modern day, low pressure ultraviolet sunlamps typically emit most of their energy in the wavelength range that is closest to the visible; that is, in the UVA range (320nm-400nm) range. The emission spectrum of sunlamps usually contains a relatively small proportion of UVB radiation. (260nm-320nm) Some critical design components and aspects of the sunlamps include: Glass Bulb (tubular envelope): Must be properly dimensioned and provides for transmission of ultraviolet energy in the range required for tanning. Phosphor Powder: In addition to proper physical properties such as particle size and aqueous suspension compatibility, the phosphor must emit in the wavelength range required for a particular tanning application. It is the phosphor that primarily determines the spectral irradiance distribution of the radiation from the lamp. Fill Gas and Pressure: The fill gas (in conjunction with the electrical control gear) determines the electrical characteristics of the lamp and has a large influence on the intensity of the radiation and the temporal depreciation of light output over the usage range. Coated Electrodes (Cathodes / Coils): Provide a surface area for cathode coating and to a great extent influence starting of the lamp and its physical life. Mercury: Mercury provides the basis for the operation of the lamp. It is through the excitation of mercury atoms and the subsequent quenching of the excited atoms in the vapor state that "light" is produced. It is the shortwave UV photons that resulting from the excitations that excite phosphor to produce light in a specific spectral range. Bases: Allow the lamp to be installed in appropriate sockets for electrical connectivity to the electrodes.