A finite model for the prediction of the UV radiation field around a linear lamp

A finite model was established to predict the radiation field around a line lamp treating contaminated air, taking into account the effects of the radius of the lamp and sleeve, as well as other physical parameters. Both irradiance and fluence rate could be calculated, and the model was validated with measured data and by comparison with a conventional extense source volumetric emission (ESVE) model. Diffuse and specular emissions for a line lamp were compared, showing that diffuse emission is more appropriate for a low pressure mercury UV lamp. Refraction by the lamp sleeve can induce a 12% increase in fluence rate near the sleeve, while reflection causes a 7% decrease. When the attenuation coefficient of a gaseous chemical is less than 0.04 m−1 the error due to ignoring its light absorption is less than 1%, within a distance of 0.2 m from the lamp.