A Radiometry Protocol for UVGI Fixtures Using a Moving-Mirror Type Gonioradiometer

Abstract

Ultraviolet germicidal irradiation (UVGI), 254 nm UV-C, is increasingly used as an infection control strategy to reduce the spread of airborne pathogens such as tuberculosis (TB), influenza viruses, and measles. With the appearance of multidrug-resistant TB and emerging infectious disease such as severe acute respiratory syndrome (SARS) and H1N1 influenza viruses, engineering controls using 254 nm UV-C lamps within specialized luminaires, herein designated UVGI fixtures, are being installed in high-risk settings such as homeless shelters, hospitals, jails and prisons, and schools. Studies have established that a relatively uniform spatial distribution of UV-C in the upper room can effectively cleanse the air of aerosolized pathogens. However, for planning purposes, the placement of multiple UVGI fixtures in a space, to achieve uniformity of UV-C energy distribution using currently available lighting software, is not yet practical because no industry-wide standard method exists for radiometric measurement of commercial UVGI fixtures. In this article, standard methods for photometry and reporting of general fluorescent lighting luminaire photometric data are adopted to provide UVGI fixture spatial emission distribution data in an electronic file format. The ultimate expectation of the authors is that the results will lead to a software program for fixture placement, comparable to and as easy to use as the corresponding software used for general interior lighting applications. To accomplish this goal, a radiometry measurement system is developed to obtain the radiant intensity distributions of UVGI fixtures in a three-dimensional space. This system includes a moving-mirror Type C goniometer, a mirror, a radiometer, a desktop computer, the mechanical control hardware, and the data acquisition/presentation software. Repeated measurements were made on each of three exemplary UVGI fixtures, and measurement variation did not exceed ± 2.0%.

Characterizing Ultraviolet Germicidal Irradiance Luminaires

“…The protocol used in this exercise follows that developed by Zhang et al . . It comprises 65 vertical angles, for 23 horizontal planes, a total of 1495 measuring points per luminaire.…”

“…Zhang et al . developed a protocol for the gonioradiometry of upper‐room UVGI luminaires based on standard photometry methods. Their experimental set‐up used a moving‐mirror Type‐C gonioradiometer.…”

“…This results in high-level irradiation on the microorganism in a defined (designed) zone, and minimum levels of irradiance on human skin and eyes to reduce the UV exposure in the lower, occupied zone of the room. Zhang et al (2) developed a protocol for the gonioradiometry of upper-room UVGI luminaires based on standard photometry methods. Their experimental set-up used a moving-mirror Type-C gonioradiometer.…”

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).…”

Upper‐Room Ultraviolet Germicidal Irradiation (UVGI) for Air Disinfection: A Symposium in Print

“…This published guideline was the impetus for the development of a computer assisted design (CAD) program, discussed at the meeting, which was modified with the assistance of Acuity Lighting (Tim Sears) for use with UVGI . Its use requires full gonioradiometry of any fixture to be incorporated into a design . This is a powerful design tool, but so far only a handful of commercial fixtures have been fully characterized.…”