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.
