What is the difference between UVA and UVB rays?

1）UVA

Long-wave UVA, with wavelengths ranging from 320 to 400 nanometers, is also known as long-wave ultraviolet radiation. It has strong penetration abilities, able to pass through glass and even 9 feet of water. It is present throughout the year, regardless of weather conditions.

Harm to the Human Body: Over 95% of UV radiation encountered by the skin on a daily basis is UVA, making it the most harmful to the skin. UVA can penetrate the epidermis and affect the dermis, causing damage to collagen and elastin proteins. The dermis cells have poor self-protective abilities, so even small amounts of UVA can cause significant harm. Over time, this can result in sagging skin, wrinkles, and visible microvascular issues.

Furthermore, UVA can activate tyrosinase, leading to immediate melanin deposition and new melanin formation, causing the skin to darken and lose its luster. UVA causes long-term, chronic, and lasting damage, resulting in premature skin aging, earning it the nickname "aging rays."

Application Areas: UVA radiation at a wavelength of 360 nm aligns with the phototactic response curve of insects and can be used to create insect traps. UVA radiation between 300-420 nm can pass through specially colored glass tubes that completely block visible light, emitting near-ultraviolet light centered around 365nm. This can be used in ore identification, stage decoration, counterfeit detection, and other applications.

2）UVB

Middle-wave UVB, with wavelengths ranging from 275 to 320 nanometers, is also known as middle-wave erythema-producing ultraviolet radiation. It has moderate penetration abilities, with the shorter wavelengths being absorbed by transparent glass. Most of the UVB radiation in sunlight is absorbed by the ozone layer, and less than 2% reaches the Earth's surface, being particularly intense during summer and midday.

Harm to the Human Body: UVB can oxidize the lipid layer that protects the epidermis, leading to dry skin. It can also cause the denaturation of nucleic acids and proteins within epidermal cells, resulting in symptoms like acute skin inflammation (sunburn), redness, and pain. Prolonged exposure can lead to skin cancer. UVB's long-term effects can also lead to melanocyte mutations, causing stubborn sunspots.

Application Areas: UVB radiation is used in UV health lamps and plant growth lamps, which emit light through specialized purple glass (blocking light below 254nm) and phosphors with peaks around 300nm.

1)UVA sterilization module

2)UVB Led Chip