Using a mathematical fluence rate model to estimate the sensor readings in a multi-lamp ultraviolet reactor

Most ultraviolet (UV) reactors are equipped with UV sensors that monitor the fluence rate or irradiance at given positions in a UV reactor. In this paper, the mathematics are developed for how to calculate an estimated sensor reading for given conditions of lamp power, lamp efficiency, coordinates of the reactor, quartz sleeves and lamps, and water quality parameters (e.g., percent transmittance) using a multiple segment summation model for the fluence rate distribution in a UV reactor. An example is presented of a 72 lamp UV reactor, and the estimated sensor readings agree well with the experimental values for three different percent transmittance values at 254 nm. Key words: UV sensors, irradiance, fluence rate, UV reactors, modeling, transmittance.