The LEAF-STATE-ANALYZER LSA-2050 is a handheld device for non-invasive leaf analysis. The device analyses three areas that are related to the state of health of the plant: (1) the extent of protection from ultraviolet and strong visible radiation, (2) the chlorophyll concentration, and (3) the maximum photochemical quantum yield of photosystem II, FV/FM. In summary, the LEAF-STATE-ANALYZER LSA-2050 provides a picture of stress effects and a plant's ability to cope with stress.