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NDVI/PRI Sensor

Note: Due to a parts shortage, NDVI sensors are currently unavailable. However, PRI sensors are still available for purchase.

 

Continuously monitor NDVI or PRI at the plot or ecosystem scale

At METER, we think you should spend less time on complexity and more time doing what matters. Apogee NDVI and PRI sensors are easy-to-use multiband radiometers that combine an ultra-rugged form with sophisticated cloud data delivery for an unbeatable price-to-performance ratio. And the best part? They’re pre-configured for use with the ZENTRA system, so you’re instantly up and running.

Low cost—low maintenance

By focusing on just two relevant bands, it’s possible to make an accurate multiband radiometer for a fraction of what a full-spectrum spectroradiometer costs. Apogee NDVI/PRI sensors are inexpensive enough to deploy multiple sensors simultaneously, so you can maximize spatial coverage and explore spatial and temporal variability in canopy structure and function.

Deploy for months or even years

Most spectrometers are delicate and expensive, making long-term field deployment risky. Apogee NDVI and PRI sensors are built for long-term exposure to the elements. Encased in a durable housing with an epoxy fill, they are watertight, weatherproof, and have fully sealed optics. Mount them on a fence post, tripod, or a meteorological tower. They’re rugged enough to leave in the field for an entire growing season or longer. 

Field ready and radiometrically calibrated

Each sensor is radiometrically calibrated to a NIST-traceable standard. Readings are output in units of radiant flux density. Calibration information is stored on board the sensor, so you never have to worry about keeping track of calibration coefficients.

Collect data and monitor remotely

To simplify your workflow, Apogee NDVI and PRI sensors are plug-and-play with ZL6 data loggers, which means automatic sensor recognition and zero programming. ZENTRA Cloud lets you monitor remote sites in near-real time from any internet-connected device. Observe field conditions, check and configure sensor and system function, or download data from the comfort of your home or office.

Work less. Measure more.

Apogee NDVI/PRI sensors are part of a complete system of affordable, easy-to-use sensors, loggers, and software that require little maintenance and put near-real-time data at your fingertips, so you can publish more and work less.

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California requires the following notice

⚠️ WARNING: This product may contain chemicals including ethylene glycol, lead, nickel, styrene and cadmium, which are known to the State of California to cause cancer, birth defects or other reproductive harm. For more information, go to www.P65Warnings.ca.gov

NDVI/PRI Sensor

Specifications

PRI SENSOR SPECIFICATIONS

Calibration factor (reciprocal of sensitivity)

Custom for each sensor and stored in firmware

NOTE: The calibration factor (reciprocal of sensitivity) and output range are all approximations and variable from sensor to sensor

Calibration uncertainty

± 5 %

Output range

SDI-12

NOTE: The calibration factor (reciprocal of sensitivity) and output range are all approximations and variable from sensor to sensor

Power supply

5.5 to 24 V DC

Wavelength ranges

Green detector = 532 nm with 10 nm FWHM*
Yellow detector = 570 nm with 10 nm FWHM*

*FWHM = full-width half-maximum

Measurement range

2x full sunlight

Measurement repeatability

Less than 1 %

Long-term drift

Less than 2 % per year

Response time

Less than 0.6 s

Field of view

S2-421-SS (upward-looking): 180°
S2-422-SS (downward-looking): 35°

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

S2-421-SS (upward-looking): 30.5 mm diameter, 37 mm height
S2-422-SS (downward-looking): 23.5 mm diameter, 43 mm height

Mass (with 5 m of cable)

S2-421-SS (upward-looking): 140 g
S2-422-SS (downward-looking): 110 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), ZL6 stereo plug termination

NDVI SENSOR SPECIFICATIONS

NDVI wavebands

650 ± 2 and 810 ± 2 nm peak wavelengths, with 10 nm and 10 nm full width half maximum (FWHM) band widths

Foreoptics

(1) Cosine correcting Teflon diffuser, hemispherical field of view
(2) Field stop, 36° field of view

Calibration

NIST traceable calibration to known spectral irradiance (W m-2 nm-2 nm-1 sr-1)

Accuracy

10% or better for spectral irradiance and radiance values

Measurement time

~ 600 ms

Dimensions

43 x 40 x 27mm

Weight

Sensor: 47 g
Sensor with 5 m cable: 170 g

Power requirements

3.6 to 15 VDC, 4 mA (reading, 300 ms), 30µA (quiescent)

Operating temperature range

-40 to 50 °C

Cable length

5 m standard, custom cable length available upon request

Connector type

3.5 mm (stereo) plug or stripped and tinned lead wires (pigtail)

Communication

SDI-12 digital sensor

Data logger compatibility (not exclusive)

METER EM60 series, ZL6 series, ZSC, ProCheck, Campbell Scientific

California requires the following notice:

⚠️ WARNING: This product may contain chemicals including ethylene glycol, lead, nickel, styrene and cadmium, which are known to the State of California to cause cancer, birth defects or other reproductive harm. For more information, go to www.P65Warnings.ca.gov

Support

Have a question or problem? Our support team can help.

We manufacture, test, calibrate, and repair every instrument in house. Our scientists and technicians use the instruments every day in our product testing lab. No matter what your question is, we have someone who can help you answer it.

Email: support.environment@metergroup.com

Phone US: +1 509-332-5600
Phone Europe: +49 89 12 66 52 0

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