Ultraviolet (UV) has been used in industry and health care for many years. The new generation of UVLED now seems to be challenging the source of traditional ultraviolet fluorescent lamps.

What is the wavelength range of UVC LED?

UVC LED wavelengths are usually defined as 200nm to 280nm.

Several problems about the UVC wavelength of deep ultraviolet UVLED sterilization

What is the "bactericidal range" of ultraviolet radiation?

According to the international ultraviolet Association, "a very important ultraviolet spectrum ('bactericidal area") for disinfection of water and air is a range that is absorbed by the DNA (some viruses are RNA). This bactericidal range is about 200-300nm.

The range of sterilization known to extend beyond 280 nm is now generally thought to extend to 300 nm, but this may change with more research. Scientists have demonstrated that ultraviolet light between 280nm and 300nm can be used for disinfection and sterilization.

Several problems about the UVC wavelength of deep ultraviolet UVLED sterilization

What is the best wavelength for disinfection?

There is a misconception that 254 nm is the best wavelength for disinfection because the peak wavelength of the low-pressure mercury lamp (determined only by the physics of the lamp) is 253.7 nm. It is generally believed that the wavelength of 265nm is the best, because this wavelength is the peak value of DNA absorption curve. However, a certain range of wavelengths can be sterilized and sterilized.

Ultraviolet mercury lamp has been considered the best choice for disinfection and sterilization. Why is this?

Historically, mercury lamp has been the only choice for disinfection and sterilization. With the progress of UV LED technology, there are new options, because LED is smaller, stronger, nontoxic, longer, more energy-efficient, and allows more switching times. This makes the solution more compact, battery powered, more portable and capable of instant all-optical output.

What is the difference between the wavelength characteristics of the UVC LED and the mercury lamp?

Low pressure mercury lamps emit nearly monochromatic light at a wavelength of 253.7nm. Low pressure mercury lamp (fluorescent lamp tube) and high pressure mercury lamp are also used for disinfection and sterilization. These lamps have wider spectral distribution, including wavelength for sterilization. UVC LED can focus on a narrow specific wavelength, which enables the solution to be tailored to specific application requirements.

Is the peak absorption wavelength of DNA different from that of bacteria?

Yes. The peak absorption wavelengths of different species are different, but most of them are about 265nm.

Can all the bacteria be eliminated by a single wave?

Yes, you can use a single wavelength. However, bacteria have different optimal absorption wavelengths.

How to determine the bactericidal effect?

The bactericidal effect is usually determined by power intensity, wavelength and duration of irradiation. For example, in water, there may be many bacteria with different optimal absorption wavelengths. For any given wavelength of bactericidal ultraviolet, it is necessary to calculate the power and time of irradiation to achieve the desired disinfection level.