Ultraviolet lamp

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An ultraviolet lamp or UV lamp for short, is a type of light emitting device which is capable of giving off ultraviolet light. UV lamps are commonly used in biology and in chemistry for UV sensitive experiments.

General

UV lamps consist of an electronic device, containing a UV light emitting source, such as mercury lamp or UV LED's. Other sources include deuterium arc lamps, mercury-xenon arc lamps, metal-halide arc lamps, tungsten-halogen incandescent lamps or xenon arc lamps. An electrical switch is used to turn on/off the lamp. If the UV lamp has two discharge lamps, a separate switch can be used to alternate between the two lamps. UV lamps can be portable (hand-held) or bulky, being powered by batteries or through a plug.

Ultraviolet LED chip can be used as crude UV lamps, though they are more commonly used in photochemistry.

Availability

Ultraviolet lamps can be purchased from a variety of electronic or hardware/dollar stores. Medical supply stores will also sell UV lamps.

UV LED chip can be found online, or in some electronic stores.

DIY UV lamp

An easy UV lamp can be made by hooking up a series of UV LEDs to a power source and an electric switch. Since the UV LEDs emit UV light on a singular wavelength, that will be the wavelength of your UV lamp.

More complex UV lamps can be made by hooking up several gas-discharge lamps inside a box.[1]

In recent years powerful UV LEDs have become available to the general consumer via eBay or other online sellers for little money. LEDs are available down to 250 nm. Both 250 nm and 270 nm UV-C LEDs are able to visualize F254-TLC plates (but 310 nm is not to any appreciable degree).[2] They have very little visible output. For viewing the fluorescence of substances usually 365 nm or 395-400 nm UV-A LEDs are used. 365 nm LEDs are more expensive but have less visible light as output and this wavelength is used in commercial TLC lamps that contain short- and longwave UV lamps. It can be recommended to use a UV pass filter in front of these types of UV-A LEDs, for example a ZWB2 filter, as the amount of visible light is drastically reduced, especially to cameras.

There are small handheld money testers which use a 365 nm UV blacklight tube. This can be swapped out for a 254 nm low pressure mercury lamp tube as a TLC light. These tubes emit in all directions however so some shielding is advised.

Projects

  • Photochemistry
  • Sterilize various equipment, materials, organic products
  • Destroy chemical wastes

Safety

UV lamps are harmful to eyes and long exposure to skin is hazardous. Proper protection, such as UV glasses, UV blocking clothing should be worn when working with UV lamps. Avoid having anything reflective on the UV illuminated area.

References

  1. https://www.youtube.com/watch?v=emFCCGlzjnQ
  2. M. Tsai, Y.-F. Lu, Y.-. Wang, J. Alloys Compd. 2010, 505(2), 818-823, https://doi.org/10.1016/j.jallcom.2010.06.147

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