Novel Measurement System for Linear Array Type UVC Germicidal System

The germicidal system is constructed using a UVC LED illumination module with a wavelength of 275 nm and a power of 1.8 mw. UVC LED has a smaller volume without heat radiation and pollution that meets the requirements of green energy and environmental protection. It is very suitable for sterilization and purification. It can destroy microbiological organisms such as bacteria, viruses, or spores, etc., of their molecular structure of DNA (deoxyribonucleic acid) and RNA (ribonucleic acid) in pathogen cells, which causes the cells to lose the ability to replicate and regenerate, thereby achieving germicidal efficacy. The UVC Germicidal System (abbreviated as UVCGS) is designed with an array of UVC LEDs. The key technologies of the UVCGSs' drive circuit is a new automatic power control system (APC) design, which can make UVC LED in constant current mode and stable electric power for operation. That is, when the power of the UVC LED changes with temperature, the current amount can be automatically adjusted by the driving circuit. So that the UVC LED can be maintained at a different temperature and still keep a stable optical power output to achieve temperature compensation purpose. The design of the drive circuit confirms that the UVCGS being operated at different temperature changes from 0 °C ~ 35 °C and with stable current and stable optical power output capability can sterilize Escherichia coli, Staphylococcus aureus, Acinetobacter baumannii, etc., achieving multiple germicidal benefits. Among them, Acinetobacter baumannii has been experimentally analyzed that within 2–20 seconds of irradiation time, under the condition of average sterilization residual amount at different heights, the proper bactericidal residual amount is about 12–13 (lethal rate is 91-92%, $\text{UVGI}=12$), and the required minimum germicidal irradiation power dose is $1500\mu \text{W}$- Sec/cm2, which meets UVGI standard values and typical lethality standards.