Calibration Uncertainty ± 10 % Measurement Repeatability Less than 1 % Non-stability (Long-term Drift) Less than 3 % per year Non-linearity Less than 1 % (up to 300 μmol mˉ² sˉ¹) Response Time Less than 1 ms Field of View 180 ˚ Spectral Range 250 to 400 nm Directional (Cosine) Response ± 10 % at 75 ˚ zenith angle Temperature Response Approximately 0.1 % per C Operating Environment 0 to 50 C, less than 90 % non-condensing relative humidity up to 30 C, less than 70 % non-condensing relative humidity from 30 to 50 C Meter Dimensions 126 mm length, 70 mm width, 24 mm height Mass 150 g Warranty 4 years against defects in materials and workmanship