Apogee SQ-512, Owner'S Manual, Page: 6 / 22

SPECIFICATIONS
Calibration Traceability
Apogee Instruments SQ-500 series quantum sensors are calibrated through side-by-side comparison to the mean
of four transfer standard quantum sensors under a reference lamp. The reference quantum sensors are
recalibrated with a quartz halogen lamp traceable to the National Institute of Standards and Technology (NIST).
SQ-512 SQ-515
Power Supply 5 to 24 V DC 5.5 to 24 V DC
Current Draw 12 V is 57 µA
Sensitivity 0.625 mV per µmol m
-2
s
-1
1.25 mV per µmol m
-2
s
-1
Calibration Factor
(Reciprocal of Sensitivity)
1.6 µmol m
-2
s
-1
per mV 0.8 µmol m
-2
s
-1
per mV
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 )
Calibrated Output Range 0 to 2.5 V 0 to 5 V
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 Less than 1 ms
Field of View 180°
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 Directional Response below)
Azimuth Error Less than 0.5 %
Tilt Error Less than 0.5 %
Temperature Response -0.11 ± 0.04 % per C (see Temperature Response below)
Uncertainty in Daily Total Less than 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
Serial # 3636 (SQ-512),
3717 (SQ-515) and above
30.5 mm diameter, 37 mm height
Dimensions
Serial # 0-3635 (SQ-512),
0-3716 (SQ-515)
24 mm diameter, 37 mm height
Mass (with 5 m of cable)
Serial # 3636 (SQ-512),
3717 (SQ-515) and above
140 g
Mass (with 5 m of cable)
Serial # 0-3635 (SQ-512),
0-3716 (SQ-515)
100 g
Cable
5 m of shielded, twisted-pair wire; TPR jacket (high water resistance, high UV stability,
flexibility in cold conditions); pigtail lead wires; stainless steel (316), M8 connector