S2-442-SS Modbus Digital Output PAR-FAR Sensor

The S2-442-SS PAR-FAR sensor is a unique two-channel digital sensor for measuring both the PAR (PPFD) and Far-red outputs of electric grow lights with Modbus communication protocol. The sensor feature

  • Product Name:S2-442-SS Modbus Digital Output PAR-FAR Sensor
  • Item No.:S2-442-SS
  • Manufacturers:Apogee
  • Country of Origin:USA

The S2-442-SS PAR-FAR sensor is a unique two-channel digital sensor for measuring both the PAR (PPFD) and Far-red outputs of electric grow lights with Modbus communication protocol. The sensor features a rugged, aluminum housing that is fully-submersible and built to withstand harsh conditions. The sensor cable includes an IP68 marine-grade stainless-steel cable connector to simplify sensor removal and replacement from permanent installations for maintenance and calibration. Typical applications of PAR-FAR sensors include measuring both the traditional PPFD photosynthetic photon flux and separately quantifying the photon flux of far-red photons (700-760 nm). The outputs include the traditional quantum flux, the far-red photon flux, and the far-red fraction (far-red photon flux density / sum of PPFD and far-red photon flux density). This sensor quantifies far-red photons, and for many applications it reduces the need for a more complex measurement with a spectroradiometer.

Power Supply:     5.5 to 24 V DC

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

Calibration Factor (reciprocal of sensitivity):     Custom for each sensor and stored in firmware

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 m⁻² s⁻¹) (PAR); Less than 1 % (up to 1000 µmol m⁻² s⁻¹) (Far-Red)

Field of View:     180˚

Wavelength Ranges:     389 to 692 nm ± 5 nm (PAR); 702 to 761 nm ± 5 (Far-Red)

Directional (Cosine) Response:     ± 2 % at 45˚; ± 5 % at 75˚ zenith angle

Temperature Response:     Less than 0.1 % per C

Housing:     Anodized aluminum body with acrylic diffuser

IP Rating:     IP68

Operating Environment:     -40 to 70 C; 0 to 100 % relative humidity

Dimensions:     30.5 mm diameter, 37 mm height

Mass (with 5 m of cable):     140 g

Warranty:     4 years against defects in materials and workmanship