Calibration Traceability
Apogee MQ series ePAR meters are calibrated through side-by-side comparison to the mean of four transfer
standard sensors under a reference lamp. The reference sensors are recalibrated with a 200 W quartz halogen
lamp traceable to the National Institute of Standards and Technology (NIST).
± 5 % (see Calibration Traceability below)
Measurement
Repeatability
Long-term Drift
(Non-stability)
Less than 1 % (up to 4000 µmol m
-2
s
-1
)
383 to 757 nm ± 5 nm (wavelengths where response is greater than 50 %; see Spectral
Response below)
Directional (Cosine)
Response
± 2 % at 45° zenith angle, ± 5 % at 75° zenith angle (see Directional Response below)
Uncertainty in Daily Total
Anodized aluminum body with acrylic diffuser
-40 to 70 C; 0 to 100 % relative humidity; can be submerged in water up to depths of 30 m
126 mm length, 70 mm width, 24 mm height
30.5 mm diameter, 37 mm height
140 g (with 5 m of lead wire)
2 m of two conductor, shielded, twisted-pair wire; additional cable available; TPR jacket
4 years against defects in materials and workmanship