An ultraviolet flashlight is a type of flashlight that emits light within the ultraviolet spectrum. It is used in a wide variety of applications, such as identifying forged documents and looking for leaks in refrigerators. The flashlight usually resembles a standard flashlight, and consists of a light emitting diode (LED) and a handle. They can come in various forms, such as small, hand-sized designs or large, lantern-type models.
Ultraviolet light (UV light) refers to light that has a wavelength that is smaller than visible light. It is called ultra violet, because violet is the color of the shortest wavelength of visible light. Ultraviolet light is found in sunlight. It is also sometimes known as black light.
There are many different types of ultraviolet flashlights. The main body of the flashlight can be made from many kinds of materials, such as aluminum or plastic. Usually waterproof, most UV flashlights run on standard batteries.
The LED is one of the most important parts of the ultraviolet flashlight. Some models have settings that allow it to be shone at variable outputs. This allows the user produce the exact amount of light needed to perform a task. The LED is usually impact-resistant, for durability. The quality of the ultraviolet flashlight's refractor can determine the smoothness of the light beam produced by the LED. The distance covered by the LED generally varies.
The ultraviolet flashlight has many different applications. It is an ideal tool to illuminate poorly lit areas. Nightclubs can use them to check admission hand stamps on patrons. Criminal investigators often use UV flashlights to search for possible evidence at a crime scene. Repairmen commonly use this tool to look for cracks or leaks in equipment located in dark areas.
These UV devices are often also used to verify the authenticity of documents. For example, items that feature a hologram to prevent forgeries — such as credit cards — can be examined using an ultraviolet flashlight. Shining the light on the hologram enables one to see a design that has been embedded in the hologram for authorization purposes.
Many ultraviolet flashlights can be dangerous if a person looks directly into them, because this can cause vision damage. Shining the flashlight onto a reflective surface, such as a mirror, can also be dangerous to eyesight. Excessive skin exposure to UV light can also be harmful, as overexposure tends to destroy Vitamin A. This is generally not a problem with UV flashlights, however, as its common applications usually do not require its use on skin for long periods of time.