The Study of Far-UVC 222-nm Excilamp and Germicidal-UVC 254-nm Low-pressure Hg Lamp: Optical Characteristics and Service Life

Optical characteristics and service life of the Germicidal-UVC (GUVC) low-pressure Hg lamp and the Far-UVC KrCl excimer lamp (FUVC excilamp) were investigated. The results showed that UV irradiance at the center of the FUVC excilamp and the GUVC lamp was 0.22 mW/cm² and 9.27 mW/cm² at a working distance of 5 cm, respectively. To achieve the same virus inactivation effect, the harmful power in range of 230~280 nm should be more than 20 times that of the FUVC excilamp without considering the UVA (320~400 nm) and UVB (280~320 nm). Furthermore, the service life was assessed under room temperature 30 ± 5 °C. It was found that the average service life at L50 (with the irradiance decay of 50%) of the FUVC excilamp and GUVC lamp was about 2, 600 and 4, 700 hours, respectively.