The PG200N is a hand held Spectral PAR (Photosynthetically Active Radiation) meter, to measure the quality and quantity of light for a new generation of indoor farmers & horticulturalists who use artificial lighting as a substitute or to complement to sunlight. The PG200N helps in getting your lighting right : quantity, intensity, colour and duration (diurnal and seasonal rhythms), and can provide comprehensive data to help collect, analyse and evaluate light data for optimal light-to-plant relationship.