SQ-514-SS: Full-Spectrum 4-20 mA output

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

  • Product Name:SQ-514-SS: Full-Spectrum 4-20 mA output
  • Item No.:SQ-514-SS
  • Manufacturers:Apogee
  • Country of Origin:USA

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