Ultraviolet Radiation: A Type of Radiation with Many Applications

Ultraviolet (UV) radiation is a form of electromagnetic radiation with wavelengths shorter than visible light but longer than X-rays.

Sources:

UV radiation is emitted from sources such as:

• Objects above 2000 degrees Celsius: Hot objects like the sun, welding torches, and furnaces.

• Mercury-vapor lamps: These are widely used in applications like sterilization and lighting.

• Electric arcs: These are electric currents that pass through a gaseous medium, generating UV radiation.

Properties:

UV radiation possesses distinctive properties:

• Strong effect on photographic film: This is the principle behind film cameras.

• Ionizes air and many other gases: This leads to the formation of ions, influencing chemical reactions.

• Excites the fluorescence of many substances: Causing fluorescence, which is utilized in fluorescent lamps.

• Induces certain chemical and photochemical reactions: For example, the production of vitamin D in the human body.

• Can induce the photoelectric effect: This forms the basis of photoelectric devices.

• Has biological effects: Causes sunburn, sunburns, and even skin cancer with prolonged exposure.

• Absorbed by water and glass, transmitted through quartz: Therefore, quartz is used in UV emission and measurement devices.

Applications:

UV radiation finds applications in various fields:

• Crack detection: It can detect small cracks on the surface of materials.

• The ozone layer absorbs most ultraviolet radiation with wavelengths below 0.3(10^-6): The ozone layer acts as a shield protecting Earth from the harmful effects of UV radiation.

Note:

Excessive exposure to UV radiation can be harmful to health. It is advisable to use sunscreen, sunglasses, and limit direct exposure to sunlight.