Quantum sensors measure light energy at the specific wavelengths plants actually use for photosynthesis. Research indicates that older lux and foot-candle meters could have error rates up to 45% when used to estimate light quantum available for plant growth. Start taking more meaningful light level measurements yourself with a low-cost Field Scout Quantum Meter.
The Field Scout Quantum Meters measure Photosynthetic Photon Flux (PPF) as µmol m-2s-1 for Photosynthetically Active Radiation (PAR) in the range of 400 to 700 nm. Quantum meters can be used in the field, laboratory, above or below plants, in growth rooms and greenhouses. The meter approximates radiation between 400 and 700 nanometers(PAR) as umol m-2s-1.