What is UV (Ultraviolet)?
Sunlight is a portion of the electromagnetic radiation given by the sun. Its spectrum spans from infrared, visible to ultraviolet, useful to all of the planet lives. The light wavelength between 400-760 nm is of the visible light that can be seen with our eyes. Light wavelength beyond 760 nm up to 5300 nm is called infrared light, and wavelength between 10-400 nm is called ultraviolet light. As we know, UV light within the range of 100-280 nm wavelength, commonly known as UV-C band, has strong effects to kill or inactive bacteria, viruses, or mould. Since the mid-20th century, it has been used primarily in medical sanitation and sterilization facilities.
Important note: UV light wavelength at 254 nm has the maximum germicidal effect against microorganisms.
How Does UV Lamp Work?
Here are two types of UV lamps that are the most popular.
1. Short-wave UV Lamp, also called Fluorescent Lamp, composed of fused quartz to emit UV-C at peaks of 253.7 nm (85-90%) and 185 nm (5-10%). These low-pressure lamps have approximately 30–40% energy efficiency, meaning that for every 100 watts of electricity consumed by the lamp, they will produce approximately 30–40 watts of total UV output. They also emit bluish-white visible light. These "germicidal" lamps are used extensively for surface disinfection in laboratories and food-processing industries, and for disinfecting water supplies.
2. LED (light-emitting diodes) UV Lamp, use semiconductor materials to produce UV light from a solid-state device. As its wavelength of emission is tuneable by adjusting the chemistry of the semiconductor material, that enables a selectivity to the emission profile to across, and beyond, the germicidal wavelength band. Within semiconductor materials advancing, that led LED UV for significant increases in the output power, energy efficiency and device lifetime since early 2010s. And due to the reduced size of LED that opens up options for small reactor systems allowing for point-of-use applications and integration into medical devices, and low power consumption of semiconductors introduce UV disinfection systems widely used more than half of the market since 2020.