Calibration and the Lamp Testing Unit LTU

FIGURE 3.4. Schematic Representation of the Lamp-Testing Unit (LTU). (Reprinted with permission from Ind. Eng. Chem. Res., 40(23), M. Salaices, B. Serrano and H I. de Lasa, Photocatalytic conversion of organic pollutants Extinction coefficients and quantum efficiencies, 5455-5464. Copyright 2001 American Chemical Society). 

FIGURE 3.5. Typical asymmetiical radiative flux axial distribution of a BL lamp. (Repiinted with permission of M. Salaices, PhD Dissertation, University of Westeni Ontario(c)2002). 

Radiometric measurements can be performed with the sensor cell facing the lamp through a 1-cm opening. The sensor is displaced along a rail placed at a set distance from the lamp axis. Radiometric measurements can also be performed rotating the lamp at several contour angles for fixed radial distances. Before each measurement, it is recommended that the lamps be wanned up for a period of 5 min to stabilize the lamp s emission. 

special care must be taken in order to use lamps that display symmetrical radiation distribution in the experiments. 

This method of measuring the irradiation reaching the reactor is aphysical technique and avoids the use of indirect methods, as the case of actinometry. Actinometry only pennits the evaluation of photons reaching the sluiry, but does not give more detailed information about the inadiation distribution in the reactor. 

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