UV disinfection to kill germs and bacteria

Germicidal disinfection by exposure to ultraviolet (UV) light is seeing rapid deployment in food, pharmaceutical, hospitality, and medical markets. Users throughout the world are convinced by the effectiveness and ease-of-use of this technology. Compared with conventional methods like chemical, steam or heat disinfection, this technique features almost unlimited adaptability. Most of the time, a complex and time-consuming integration in existing systems is not necessary, so investment and operating costs are greatly reduced.

UV irradiation kills a broad range of microbes by breaking the molecular bonds that hold the organism’s DNA together.

Microbes have an absorption maximum of 263 nm. Unfortunately, there are no simple, low-cost light sources available for this wavelength. Mercury (Hg) lamps have a high output at 254 nm and especially the low-pressure versions are quite cost-effective. This is why they are the most utilized lamp type in low to medium intensity germicidal applications such as food processing, low volume water treatment, and medical service and manufacturing.

Light sources with higher powers are needed for larger disinfection applications. For example, in large-volume municipal water treatment facilities, medium pressure UV lamps are utilized. They have greater intensities and a broader spectral output. No matter which type of UV lamp is used, to assure its effectiveness, it is essential to check the output at 254 nm regularly.

International Light Technologies (ILT) provides various radiometers to determine the effective irradiance of UV light sources. We offer optimized radiometers for all major UV sources as well as low, medium and high pressure mercury lamps.

The corresponding sensors come in the following configurations:

• Narrow measuring range around 254 nm
• Effective germicidal UV light measurements conforming to the IES Luckiesh and DIN standards
• Unfiltered sensors calibrated at 254 nm for testing low pressure mercury lamps where 95% of the output is at 254 nm

All sensors are optimized for a specific spectral range by using suitable filters and optics. The sensor calibration is conforming to ISO/IEC 17025.

photonics@lot-oriel.com