All Apogee IR sensors are NIST traceable and include a calibration certificate. Sensors are calibrated to a custom blackbody cone. Research-grade sensors feature a measurement uncertainty of ± 0.2 C from -30 to 65 C when the sensor (detector) temperature is within 20 C of the surface (target) being measured. Commercial-grade sensors have a measurement uncertainty of ± 0.5 C from 0 to 50 C when the sensor is within 20 C of the surface. Radiometers are only sensitive from 8 to 14 µm (atmospheric window) to minimize the influence of water vapor and CO₂ on the measurement.