6
SPECIFICATIONS
Calibration Traceability
Apogee Instruments SQ-500 series quantum sensors are calibrated through side-by-side comparison to the mean of four
Apogee model SQ-500 transfer standard quantum sensors under high output T5 cool white fluorescent lamps. The transfer
standard quantum sensors are calibrated through side-by-side comparison to the mean of at least three LI-COR model LI-
190R reference quantum sensors under high output T5 cool white fluorescent lamps. The reference quantum sensors are
recalibrated on a biannual schedule with a LI-COR model 1800-02 and quartz halogen lamp that is traceable to the National
Institute of Standards and Technology (NIST).
Resolution 0.1 µmol m-2 s-1
Calibration Factor Custom for each sensor and stored in the firmware
Calibration Uncertainty ± 5 % (see calibration Traceability below)
Measurement Range 0 to 4000 µmol m-2 s-1
Measurement Repeatability Less than 1 % (up to 4000 µmol m-2 s-1)
Long-term Drift
(Non-stability)
Less than 2 % per year
Non-linearity Less than 1 % (up to 4000 µmol m-2 s-1)
Response Time Software updates every second
Field of View 180º
Spectral Range 389 to 692 nm ± 5 nm (wavelengths where response is greater than 50 %)
Spectral Selectivity Less than 10 % from 412 to 682 ± 5 nm (see Spectral Response below)
Directional (Cosine) Response ± 2 % at 45º zenith angle, ± 5 % at 75º zenith angle (see Cosine Response below)
Temperature Response -0.11± 0.03 % per C (see Temperature Response below)
Azimuth Error Less than 0.5 %
Tilt Error Less than 0.5 %
Detector Blue-enhanced silicon photodiode
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 24 mm diameter, 37 mm height
Mass Sensor head weighs 90 g
USB Cable 4.6 m (15 ft)
Current Draw (when Logging) 61 mA
