Fig. 4

Integrated irradiance (mean and standard deviation of five measurements) of the three lamps at 1 m distance from the center of the luminous elements in three different positions: on the axis orthogonal to the luminous elements, on an axis inclined at 60° to the orthogonal axis in the plane orthogonal to the major axis of the luminous elements and on an axis inclined at 60° to the orthogonal axis in the plane containing the major axis of the luminous elements