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S2-111 Upward-Looking NDVI Sensor

Updated:2025-03-13

Brand:APOGEE
Model: S2-111
Description: The S2-111 NDVI sensor is a unique two-channel sensor for measuring 650 nm (Red) and 810 nm (NIR) and is self-powered. The sensor features a rugged, aluminum housing that is fully-submersible and buil
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Product Details

S2-111 Upward-Looking NDVI Sensor Introduction：

user's manual

The S2-111 NDVI sensor is a unique two-channel sensor for measuring 650 nm (Red) and 810 nm (NIR) and is self-powered. 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 NDVI sensors include measuring monitoring plant canopies. NDVI is related to leaf area of the plant canopy and canopy chlorophyll content of leaves and is often used to monitor green up in the spring and senescence in the fall.

The analog version of this sensor (S2-111) comes with the inline cable connector placed 30 cm from the sensor head for either standard use as a long-cable pigtail sensor, or for use with our microCache Bluetooth Micro Logger by unscrewing the connector, discarding the long section of cable and then screwing the sensor to the mating connector on the microCache.

S2-111 Technical Drawing：

S2-111 Specifications:

Power Supply	Self-powered
Output (sensitivity)	14 mV per W m?2 (Red); 20 mV per W m?2 (NIR)
Calibration Factor (reciprocal of sensitivity)	0.07 W m?2 nmˉ1 per mV (Red); 0.05 W m?2 nmˉ1 per mV (NIR)
Calibration Uncertainty	± 5 %
Output Range	40 mV (Red); 40 mV (NIR)
Wavelength Ranges	Red detector = 650 nm ± 5 nm with 65 full-width half-maximum; NIR detector = 810 nm ± 5 nm with 65 full-width half-maximum
Measurement Range	2x full sunlight
Measurement Repeatability	Less than 1 %
Long-term Drift (Non-stability)	Less than 2 % per year
Response Time	Less than 1 ms
Field of View	180?
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