Description
Measure photon flux density (PFD) from 340-1040 nm
Apogee’s new extended range photon flux density (PFD) sensors are 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 UV and far-red LEDs to achieve various disease control and photomorphogenic effects. The extended range filter of the SQ-620 allows it to measure photons from UV and Far-red. The 1040 nm top cutoff also means the sensor will measure the thermal output of HPS fixtures and other broad-spectrum lights above the range that influences plants; therefore, the sensor is intended only for use in LED environments.
Spectral Response
The Extended Range PFD sensor (model SQ-620) has a spectral range of 340 to 1040 nm ± 5 nm. The extended spectral response increases the accuracy of LED measurements. The spectral responses can be seen in the graph below.
Accurate, Stable Measurements
Sensors are cosine-corrected to maintain their accuracy when radiation comes from low zenith angles. The sensors measure PFD with a cosine response accurate within ± 5 % at 75° zenith angle. Long-term non-stability determined from multiple replicate quantum sensors in accelerated aging test and field conditions is less than 2 % per year.
Typical Applications
Typical applications of traditional quantum sensors include incoming PPFD measurement over plant canopies in outdoor environments or in greenhouses and growth chambers, and reflected or under-canopy (transmitted) PPFD measurement in the same environments. The Extended Range Quantum Sensor detailed in this manual uses a detector that is sensitive to radiation up to about 1100 nm, well beyond the range of wavelengths that influence photosynthesis and plant responses. This means this particular sensor should only be used for photon flux density measurements under LEDs.
Rugged, Self-cleaning Housing
Patented domed shaped sensor head (diffuser and body) facilitate runoff of dew and rain to keep the sensor clean and minimize errors caused by dust blocking the radiation path. Sensors are housed in a rugged anodized aluminum body and electronics are fully potted.
Calibration
To ensure accuracy each sensor is carefully calibrated in controlled conditions and traceable to NIST reference standards. The full-spectrum sensors are pre-calibrated for all light sources.
Mounting
The AL-120 Solar Mounting Bracket with Leveling Plate facilitates mounting the sensor to a mast or pipe. The AL-100 Solar Sensor Leveling Plate is designed to level the sensor while sitting on a flat surface or mounting to a surface.
Output Options
Apogee currently offers one analog model available for sale on our website with multiple outputs and measurement ranges coming soon. Please call for availability. Sensors are also available attached to a hand-held meter with digital readout.
High Quality Cable
Pigtail-lead sensors feature an IP68, marine-grade stainless-steel cable connector approximately 30 cm from the head to simplify sensor removal for maintenance and recalibration. Cable is shielded-twisted pair wire with a TPR jacket for high water resistance, UV stability, and flexibility in cold conditions.
Warranty and Support
All Apogee products are backed by an industry-leading four year warranty and outstanding customer support.
Specifications
| SQ-620(Analog) | SQ-622(0-2.5V) | SQ-625(0-5V) | SQ-627(SI-12) | |
|---|---|---|---|---|
| Power Supply | Self-powered | 12 to 24 V DC | 5 V USB power source | 5.5 to 24 V DC |
| Current Draw | – | Maximum of 20 mA | 61 mA when logging | 1.4 mA (quiescent), 1.8 mA (active) |
| Sensitivity | 0.05 mV per µmol m-2 s-1 | 0.004 mA per µmol m-2 s-1 | – | – |
| Output Type | 0 to 200 mV | 0 to 2.5 V | 0 to 5 V | SDI-12 |
| Resolution | – | – | 0.1 µmol m-2 s-1 | – |
| Calibration Factor | 20 µmol m-2 s-1 per mV | 250 µmol m-2 s-1 per mA | Custom for each sensor and stored in the firmware | Custom for each sensor and stored in the firmware |
| Calibration Uncertainty | ± 5 % | ± 5 % | ± 5 % | ± 5 % |
| Measurement Range | 0 to 4000 µmol m-2 s-1 | 0 to 4000 µmol m-2 s-1 | 0 to 4000 µmol m-2 s-1 | 0 to 4000 µmol m-2 s-1 |
| Measurement Repeatability | Less than 0.5 % | Less than 0.5 % | Less than 0.5 % | Less than 0.5 % |
| Long-term Drift per Year | Less than 2 % per year | Less than 2 % per year | Less than 2 % per year | Less than 2 % per year |
| Non-linearity | Less than 1 % (up to 4000 µmol m-2 s-1) | Less than 1 % (up to 4000 µmol m-2 s-1) | Less than 1 % (up to 4000 µmol m-2 s-1) | Less than 1 % (up to 4000 µmol m-2 s-1) |
| Response Time | Less than 1 ms | Less than 1 ms | Software updates every second | Less than 0.6 s |
| Field of View | 180° | 180° | 180° | 180° |
| Spectral Range | 340 to 1040 nm ± 5 nm (wavelengths where response is greater than 50 % of maximum) | 340 to 1040 nm ± 5 nm (wavelengths where response is greater than 50 % of maximum) | 340 to 1040 nm ± 5 nm (wavelengths where response is greater than 50 % of maximum) | 340 to 1040 nm ± 5 nm (wavelengths where response is greater than 50 % of maximum) |
| Directional (Cosine) Response | ± 2 % at 45°; ± 5 % at 75° zenith angle | ± 2 % at 45°; ± 5 % at 75° zenith angle | ± 2 % at 45°; ± 5 % at 75° zenith angle | ± 2 % at 45°; ± 5 % at 75° zenith angle |
| Azimuth Error | Less than 0.5 % | Less than 0.5 % | Less than 0.5 % | Less than 0.5 % |
| Tilt Error | Less than 0.5 % | Less than 0.5 % | Less than 0.5 % | Less than 0.5 % |
| Temperature Response | -0.11 ± 0.04 % per C | -0.11 ± 0.04 % per C | -0.11 ± 0.04 % per C | -0.11 ± 0.04 % per C |
| Uncertainty in Daily Total | Less than 5 % | Less than 5 % | Less than 5 % | Less than 5 % |
| Housing | Anodized aluminum body with acrylic diffuser | Anodized aluminum body with acrylic diffuser | Anodized aluminum body with acrylic diffuser | Anodized aluminum body with acrylic diffuser |
| IP Rating | IP68 | IP68 | IP68 | IP68 |
| Operating Environment | -40 to 70 C; 0 to 100 % relative humidity; can be submerged in water up to depths of 30 m | -40 to 70 C; 0 to 100 % relative humidity; can be submerged in water up to depths of 30 m | -40 to 70 C; 0 to 100 % relative humidity; can be submerged in water up to depths of 30 m | -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 | 30.5 mm diameter, 37 mm height | 30.5 mm diameter, 37 mm height | 30.5 mm diameter, 37 mm height |
| Mass (with 5 m of cable) | 140 g | 140 g | 140 g | 140 g |
| Warranty | 4 years against defects in materials and workmanship | 4 years against defects in materials and workmanship | 4 years against defects in materials and workmanship | 4 years against defects in materials and workmanship |
