Apogee line quantum sensors measure a spatial average of photosynthetically active radiation (PAR). The SQ-301X-SS has a sensor bar with 10 sensors and is self-powered with a 0 to 250 mV output. The sensor is calibrated for use in sunlight and some broadband light sources only.  The sensor housing design features an integrated bubble level and is fully potted, making the sensor water- and weatherproof. Typical applications include photosynthetic photon flux density (PPFD) measurement over plant canopies in outdoor environments, greenhouses, and growth chambers, and reflected or under-canopy (transmitted) PPFD measurements in the same environments. Sensor includes IP68 marine-grade stainless-steel cable connector 30 cm from head to simplify sensor removal and replacement for maintenance and recalibration.