The main reasons for testing light intensity are to ensure that minimum standards of illumination are being met, and to determine appropriate exposure times in photography and cinematography.
Four commonly encountered situations are set out,from which i will describe on way to test light intensity;
WEATHER MONITORING:
While many light meters are configured for incandescent light they are still useful for providing comparisons outdoors. A meter could for example produce records showing the difference in intensity between the summer and winter solstice. Mapping light intensities in an area designated for solar arrays could help determine the optimal location for each panel. Those involved in agriculture may benefit from identifying areas of lower light intensity within a greenhouse.