The SQ-225 is an amplified original quantum sensor with a 0 to 5 V output that has been calibrated for use with electric lights. The sensor features a rugged, self-cleaning sensor housing design. Typical applications include PPFD (Photosynthetic Photon Flux Density) measurement over plant canopies in outdoor environments, greenhouses, and growth chambers, and reflected or under-canopy (transmitted) PPFD measurements in the same environments. Quantum sensors are also used to measure PAR (Photosynthetically Active Radiation)/PPFD in aquatic environments, including salt water aquariums where corals are grown. Sensor includes IP67 marine-grade stainless-steel cable connector 30 cm from head to simplify sensor removal and replacement for maintenance and recalibration.
Power Supply 5.5 to 24 V DC; current draw of 10 µA
Sensitivity 2 mV per µmol mˉ² sˉ¹
Calibration Factor 0.5 µmol mˉ² sˉ¹ per mV (reciprocal of sensitivity)
Calibration Uncertainty ± 5 %
Calibrated Output Range 0 to 5 V
Measurement Repeatability Less than 0.5 %
Non-stability (Long-term Drift) Less than 2 % per year
Non-linearity Less than 1 % (up to 2500 µmol mˉ² sˉ¹; maximum PPFD measurement is 2500 µmol mˉ² sˉ¹)
Response Time Less than 1 ms
Field of View 180˚
Spectral Range 410 nm to 655 nm (wavelengths where response is greater than 50 % of maximum)
Spectral Selectivity Less than 10 % from 469 to 655 nm
Directional (Cosine) Response ± 5 % at 75˚ zenith angle
Temperature Response 0.06 ± 0.06 % per C
Operating Environment -40 to 70 C; 0 to 100 % relative humidity; can be submerged in water up to depths of 30 m
Dimensions 24 mm diameter, 28 mm height
Mass 100 g (with 5 m of lead wire)
Cable 5 m of shielded, twisted-pair wire with TPR jacket (high water resistance, high UV stability, flexibility in cold conditions)
Warranty 4 years against defects in materials and workmanship
