SQ-422-SS Modbus Digital Output Quantum Sensor

The SQ-422 sensor outputs a digital signal using Modbus RTU protocol over RS-232 and RS-485. The sensor is calibrated for sunlight and electric lights, selectable through Modbus commands, and has a co

  • Product Name:SQ-422-SS Modbus Digital Output Quantum Sensor
  • Item No.:SQ-422-SS
  • Manufacturers:Apogee
  • Country of Origin:USA

The SQ-422 sensor outputs a digital signal using Modbus RTU protocol over RS-232 and RS-485. The sensor is calibrated for sunlight and electric lights, selectable through Modbus commands, and has a command that automatically applies the immersion effect correction factor for underwater measurements. 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.

Input Voltage Requirement:     5.5 to 24 V DC

Average Max Current Draw:     RS-232 quiescent 36.87 mA, active 37.06 mA; RS-485 quiescent 37.37 mA, active 42.30 mA

Calibration Uncertainty:     ± 5 %

Measurement Repeatability:     Less than 1 %

Long-term Drift:     Less than 2 % per year

Non-linearity:     Less than 1 % (up to 4000 µmol mˉ² sˉ ¹)

Field of View:     180˚

Spectral Range:     410 to 655 nm ( wavelengths where response is greater than 50 % fo maximum)

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:     30.5 mm diameter, 37 mm height

Mass (with 5 m of cable):     140 g

Cable:     5 m of two conductor, shielded, twisted-pair wire, additional cable available in multiples of 5 m; TPR jacket (high water resistance, high UV stability, flexibility in cold conditions); pigtail lead wires

Warranty:     4 years against defects in materials and workmanship