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
这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.
典型应用
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.
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.
