V-C radiation is highly germicidal because it is absorbed by the DNA of microorganisms which destroys its structure. Referred to as ultraviolet germicidal irradiation (UVGI), UV-C wavelengths around (260-270) nm are most effective in combating airborne bacteria, viruses and other microorganisms such as mildews and yeasts. Disinfecting the air can prevent the transmission of a variety of airborne infections such as tuberculosis and pandemic influenza. It can also prevent contamination of raw materials and food. Therefore, UV-C air disinfection systems are being increasingly used within healthcare environments, public places, industry, and research facilities.
Our Clusterpartner Gigahertz Optik GmbH, as a manufacturer of suitable light measurement technology for measuring UV radiation, provides support for both manufacturers and installers of UV air disinfection systems. Manufacturers need to optimise the efficacy of the UV germicidal action of air purification systems whilst ensuring no hazard is presented to occupants. New developments in germicidal UV sources, of particular note are UV-C LED arrays (265-280) nm and far UV lamps such as excimer KrCl (222nm), require new calibration strategies in order to allow low measurement uncertainties. Gigahertz offers spectral mismatch correction for all used UV sources.
Their specialist UV-C detectors and meters (UVC Radiometers) are designed to withstand the high-energy UV radiation present within air disinfection systems whilst offering the dynamic range to enable low level hazard measurements. To measure the irradiance of such extended sources, radiometers must be designed with a cosine field of view function. The required cosine-correction optics and photodetector components must also be pre-aged because of the high-energy UV radiation. Occupant safety must be ensured for rooms fitted with ceiling-mounted air disinfection systems. The monitoring of exposure to UV-C of long-term occupants (e.g. healthcare workers) within rooms fitted with air purification can be achieved with the use of personal dosimeters such as the X2000 dosimeter. For spectral measurements our high end spectroradiometers like the BTS2048-UV are recommended.
Large Research Project about UV-C Devices
As a contractor of the Federal Office for Radiation Protection in Germany (BfS), they have made extensive measurements in a large study. A total of 41 disinfection devices that work with UV-C radiation were tested. Traceable measurements were performed including measurement uncertainty evaluations according to JCGM 100:2008 and JCGM 101:2008 and a conformity assessment according to ILAC-G8:09/2019. The corresponding risk groups were analyzed according to DIN EN IEC 62471 and evaluation of the framework of DIN/TS 67506 was made. Additionally, some upper air devices were tested according to DIN EN ISO 15858 and finally, DIN EN 60335-2-65 was applied.
A comprehensive report with the measurement data and the framework of product standards and laws was published by the BfS. Further information can also be found in the BfS press release
All measurements were performed with their low stray light BTS2048-UV spectroradiometers with OoR Filter method and combined stray light correction matrix as well as with our UV-37 series detectors.
For more information visit our clusterpartner website.
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