SQ-617-SS 400-750 nm SDI-12 ePAR Sensor

Apogee's newest, cutting-edge ePAR sensor was created in 2021 as an upgrade to our ePFD sensor and designed to measure the newly defined 400-750 nm ePAR radiation range that research has shown to be photosynthetically active, beyond the traditional 400-700 nm range. The SQ-617 ePAR is a digital sensor 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 ePAR sensors include measuring total ePAR intensity over plant canopies in all growing environments, monitoring and adjusting grow lights, and researching plant morphogenic activity and photobiology. Many next generation LED fixtures, the sun, and other light sources emit these newly confirmed Far-red photosynthetic wavelengths, but they have not been measurable by traditional 400-700 nm PAR meters until now.

The analog version of this sensor (SQ-610) 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.

How is the SQ-617 different from previous Apogee quantum sensors?
The SQ-617 is an extended photosynthetically active radiation (ePAR) SDI-12 sensor with a spectral range of 400 to 750 nm ± 5 nm, which can be seen in the graph below.

Where is the SQ-617 used?
The SQ-617 is used for measuring the newest generation of LED grow lights with wavelengths outside the traditional 400-700 nm PAR range. Research has shown the value of adding far-red LEDs to fixtures to achieve various disease control and photomorphogenic effects. The extended range filter of the SQ-617 allows it to measure photons from PAR and Far-red.

Specification

• Input Voltage: 5.5 to 24 V
• DC Current Draw: 1.4 mA (quiescent), 1.8 mA (active)
• Calibration: Uncertainty ± 5 %
• Measurement Range: 0 to 4000 µmol mˉ² sˉ¹
• Measurement Repeatability: Less than 0.5 %
• Long-term Drift: Less than 2 % per year
• Non-linearity: Less than 1 % (up to 4000 µmol m⁻² s⁻¹)
• Response Time: Less than 1 ms
• Field of View: 180˚
• Spectral Range: 394 to 747 ± 5 nm (wavelengths where response is greater than 50 %)
• Directional (Cosine): Response ± 2 % at 45˚; ± 5 % at 75˚ zenith angle Azimuth Error: Less than 0.5 %
• Tilt Error: Less than 0.5 %
• Temperature Response: -0.11 ± 0.04 % per C
• Uncertainty in Daily Total: Less than 5 %
• Housing: Anodized aluminum body with acrylic diffuser
• IP Rating: IP68
• 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; pigtail lead wires; stainless steel (316), M8 connector
• Warranty: 4 years against defects in materials and workmanship
• Manufactured: Assembled in the USA