The SQ-514 is an amplified full-spectrum quantum sensor with a 4 to 20 mA output. The sensor was designed for use in environments with significant background electrical noise that can be found in many industrial applications. 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 IP68 marine-grade stainless-steel cable connector 30 cm from head to simplify sensor removal and replacement for maintenance and recalibration.
How is the SQ-514 different from previous Apogee quantum sensors?
The SQ-514 is a full-spectrum quantum sensor with a spectral range of 389 to 692 nm ± 5 nm, which can be seen in the graph below. This improved spectral response increases the accuracy of LED measurements.
Where is the SQ-514 used?
The SQ-514 is used to measure incoming PPFD measurements in outdoor environments, greenhouses, growth chambers, and aquariums.
Power Supply： 12 to 24 V DC
Current Draw： maximum of 20 mA
Output (sensitivity)： 0.004 mA per µmol mˉ² sˉ¹
Calibration Factor： 250 µmol mˉ² sˉ¹ per mA
Calibration Uncertainty： ± 5 %
Output Range： 4 to 20 mA
Measurement Repeatability： Less than 0.5 %
Long-term Drift： Less than 2 % per year
Non-linearity： Less than 1 % (up to 4000 µmol mˉ² sˉ¹)
Response Time： Less than 1 ms
Field of View： 180˚
Spectral Range： 391 to 695 nm ± 5 nm (wavelegths where response is greater than 50 % of maximum)
Spectral Selectivity： Less than 10 % from 412 to 682 nm ± 5 nm
Directional (Cosine) Response： ± 2 % at 45˚ zenith angle, ± 5 % at 75˚zenith angle
Azimuth Error： Less than 0.5 %
Tilt Error： Less than 0.5 %
Temperature Response： -0.1 % per C
Uncertainty in Daily Total： Less than 5 %
Detector： Blue-enhanced silicon photodiode
Housing： Anodized aluminum body with acrylic diffuser
IP Rating： IP68
Operating Environment： -40 to 70 C; 0 to 100 % relative humidity; can be submerged in water up to depths of 30 m
Dimensions： 30.5 mm diameter, 37 mm height
Mass (with 5 m of cable)： 140 g
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
