ISO 9060:2018 Class C (fast response) Power Supply 12 V DC for heater Current Draw 15.4 mA Heater 780 Ω, 15.4 mA current draw and 185 mW power requirement at 12 V DC Sensitivity 0.2 mV per W mˉ² Calibration Factor (reciprocal of output) 5 W mˉ² per mV Calibration Uncertainty at 1000 W mˉ² Less than 3 % Calibrated Output Range 0 to 400 mV Measurement Repeatability Less than 1 % Non-stability (Long-term Drift) Less than 2 % per year Non-linearity Less than 1 % (up to 2000 W mˉ²) Response Time Less than 1 ms Field of View 180˚ Spectral Range 360 to 1120 nm (wavelengths where response is 10 % of maximum) Directional (Cosine) Response ± 5 % at 75˚ zenith angle Temperature Response 0.04 ± 0.04 % per C 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, 33 mm height Mass (with 5 m of cable) 90 g Warranty 4 years against defects in materials and workmanship