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S2-441 SDI-12 PAR-FAR Sensor

Updated:2025-03-13

Brand: APOGEE
Model: S2-441
Description: The S2-441 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 SDI-12 communication protocol. The sensor features a
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Product Details

S2-441 SDI-12 PAR-FAR Sensor Introduction：

Specification Sheet

The S2-441 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 SDI-12 communication protocol. The sensor features a rugged, aluminum housing that is fully-submersible and built to withstand harsh conditions, and high-quality cable terminating in pre-tinned pigtail leads for easy connection to dataloggers and controllers. 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 (700-750 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.

S2-441 SDI-12 PAR-FAR Sensor drawing：

S2-441 SDI-12 PAR-FAR Sensor Specifications:

Power Supply	5.5 to 24 V DC
Current Draw	1.4 mA (quiescent), 1.8 mA (active)
Calibration Factor (reciprocal of sensitivity)	Custom for each sensor and stored in firmware
Calibration Uncertainty	± 5 %
Output Range	SDI-12
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)
Response Time	Less than 0.6 s
Field of View	180?
Spectral Ranges	389 to 692 nm ± 5 nm (PAR); 700 to 750 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
Cable	5 m of shielded, twisted-pair wire; TPR jacket (high water resistance, high UV stability, flexibility in cold conditions); pigtail lead wires; stainless steel (316), M8 connector
Warranty	4 years against defects in materials and workmanship
Manufactured	Made in the USA