SPECIFICATIONS
Calibration Traceability
Apogee SQ series quantum sensors are calibrated through side-by-side comparison to the mean of transfer
standard quantum sensors under a reference lamp. The reference quantum sensors are recalibrated with a 200 W
quartz halogen lamp traceable to the National Institute of Standards and Technology (NIST).
SQ-422
Input Voltage Requirement
5.5 to 24 V DC
Average Max Current Draw
RS-232 quiescent 36.87 mA, active 37.06 mA;
RS-485 quiescent 37.37 mA, active 42.30 mA
Calibration Uncertainty
± 5 % (see Calibration Traceability below)
Measurement Repeatability
Less than 1 %
Long-term Drift
(Non-stability)
Less than 2 % per year
Non-linearity
Less than 1 % (up to 4000 µmol m
-2
s
-1
)
Field of View
180°
Spectral Range
410 to 655 nm (wavelengths where response is greater than 50% of maximum; see Spectral
Response below)
Directional (Cosine) Response
± 5 % at 75° zenith angle (see Cosine Response below)
Temperature Response
0.06 ± 0.06 % per C (see Temperature Response below)
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 diameter
Mass (with 5 m of cable)
140 g
Cable
5 m of two conductor, shielded, twisted-pair wire; TPR jacket (high water resistance, high
UV stability, flexibility in cold conditions); pigtail lead wires; stainless steel (316), M8
connector