The 819D-SL-5.3-CAL2 is a NIST traceable calibrated integrating sphere detector using a 5.3 inch integrating sphere with a high performance silicon photodetector. The input port size is 0.5 in. diameter and the wavelength range is 400 – 1100 nm. For a very high power level, elevated temperature of the integrating sphere system can affect the measurement accuracy so the sphere must be temperature controlled.