| UV light systems provide ultraviolet (UV) | | | | Spot or wand systems are benchtop units that |
| light for curing, material identification, | | | | provide a UV beam with a small spot size for |
| forensic location, disinfection and material | | | | selective curing applications. Wall or |
| processing applications. Some UV light | | | | ceiling mounted UV systems disinfect an air |
| systems use ultraviolet radiation to initiate | | | | stream as UV light irradiates the air |
| chemical reactions and cure adhesives, | | | | circulating through the room. HVAC or |
| coatings, and resins. Others use the | | | | duct-mounted systems are also available. |
| fluorescent response of chemicals, water | | | | |
| tracers, markers or inks, minerals and | | | | UV light systems produce ultraviolet |
| biological specimens to identify the presence | | | | radiation falling into one to three UV bands: |
| of specific material types. For example, | | | | UVA, UVB and UVC. UVA is the near or long |
| forensic scientists use UV light systems to | | | | wave UV band (~315 to 400 nm). Also known as |
| locate and identify materials or trace | | | | black light, UVA makes certain pigments |
| chemicals in arson accelerants or tagging | | | | fluoresce. UVA has little effect on pathogens |
| dyes. UV light is also an essential tool in | | | | and no effect on human tissue. UVB is the |
| thin-layer chromatography (TLC), a process | | | | middle UV band (~280 to 315 nm). It |
| that chemists use to identify the components | | | | inactivates a moderate amount of pathogens, |
| in a mixture. Medical, pharmaceutical, and | | | | but is not as effective as UVC in destroying |
| public health personnel use UV disinfection | | | | bacteria. Prolonged exposure to UVB results |
| systems and ultraviolet germicidal | | | | in blistering of the skin and cornea damage. |
| irradiation (UVGI) to sanitize air, water, | | | | UVC is the germicidal or short wave UV band |
| and transparent materials or surfaces. UV | | | | (~200 to 280 nm). When used correctly, UVC or |
| light systems are also used in specialized or | | | | UVGI inactivates pathogens by destroying |
| proprietary applications. | | | | their DNA and RNA, rendering the microbes |
| | | | impotent. The ideal wavelength for |
| UV light systems are available in a variety | | | | eradicating pathogens is 253.7 nm. Some UV |
| of configurations. Curing chambers consist of | | | | light systems also produce visible or |
| a power supply, light source and enclosure or | | | | UV-visible light in the blue green region |
| chamber that provides a work surface and | | | | (~395 to 455 nm). Visible light is useful for |
| shields the operator from radiation. UV | | | | adhesives with dual UV/visible cure |
| conveyors or continuous systems consist of a | | | | capability. Products that produce ultraviolet |
| belt conveying unit, power supply and UV | | | | light falling into the vacuum UV (VUV) band |
| light source, as well as an enclosure that is | | | | (100 to 200 nm) are also available. |
| open on both ends, which allows products or | | | | |
| sheets to pass through the system. Hand held | | | | Selecting UV light systems requires an |
| or portable UV devices are useful for repair | | | | analysis of lamp output power, lamp |
| and testing in field, laboratory, plant | | | | intensity, and product features. Some devices |
| floor, and other settings where | | | | can be programmed or have a computer |
| transportation of large systems is | | | | interface for programming, control or data |
| impractical. Flood or focused UV sources or | | | | acquisition. Others have integral or optional |
| modules are also integrated in production | | | | filters, meters or timers, and can feed |
| lines. Process or line mounted UV systems | | | | multiple wands. Specialized equipment can |
| include a power supply, light source and | | | | expose a product or material to light from |
| flange, cartridge mounting or fitting, web | | | | multiple directions. Pulsed UV light systems |
| system, coating line, and conveyor lines or | | | | and products that use light emitting diodes |
| tanks that transport chemicals, plastic film, | | | | (LEDs) as a light source are also available. |
| or other transparent media for processing. | | | | |