Characterizing Ultraviolet Germicidal Irradiance Luminaires

Abstract

In upper‐room ultraviolet germicidal irradiance (UVGI) design, irradiance is an important characteristic, with two opposing dominant dynamics: high‐level irradiation on the microorganism and minimum levels of irradiance on human skin and eyes. The use of high‐level ray‐tracing procedures is followed in establishing radiance and irradiance levels. The main constants in a room influencing these calculations are the spectral and spatial characteristics of the radiation sources in the inter‐reflecting surfaces inside the luminaire, as well as the surfaces in the room. The most important characteristic to be determined for the radiation source prior to calculations is its spatial radiant intensity distribution. This characterization is performed using a gonioradiometer. The complexity of the physical construction of the luminaire will determine the extent to which measurements have to be taken. Accurate gonioradiometer readings provide the required radiant intensities in all directions for computer‐aided design (CAD), and can also be used to determine the total radiant flux leaving the luminaire, as well as calculating isoirradiance surfaces around the UVGI luminaire. This study will present a laboratory experimental approach to deriving the radiant intensity distribution of a UVGI luminaire. The UVGI luminaire is then characterized in situ, and compared with the gonioradiometric output.

Preliminary Study on Microbial Deterioration Control and Effectiveness Evaluation in the Neolithic Prehistoric Archaeological Site of Dadiwan, Northwest China

“…This is because the biofilm by microbial filaments will block the effective penetration of UV to deeper layers, preventing UV light from acting deep in microbial colonies. Previous studies have shown that the disinfectant effects of UV light were affected by installation positions, effective distance, and exposure time [80][81][82][83][84][85]. It has been reported that viruses show the lowest resistance to UV light, followed by bacteria, and disinfection of fungi exposed to UV light requires much more time compared to bacteria [86][87][88].…”

The influence of UV-LED lamps radiation on indicators of microflora in university auditoriums

“…Upper-air UVC fixtures can vary widely in their luminaire efficiency factors, which rates the performance of emitted UVC from a fixture. Zhang et al (2012) developed a protocol and performed gonioradiometric measurements (i.e., measuring both radiance and irradiance at concurrent angles) for upper-air UVGI fixtures, which is now being used to test total UVC fixture output (Leuschner and Salie 2013). These gonioradiometric measurements are reported in standard IES format compatible with computer-aided design (CAD) lighting software adapted for use with upper room UVC devices (Rudnick et al 2012;Vincent et al 2013).…”