Precision UV-A Radiometer MS-212A is designed to measure an amount of UV-A radiation with high reliability of NIST traceable. The combination of well-designed filter and GaAsP photodiode contribute the high performance to measure UV-A between 315 and 400nm, which accounts for 4 to 5% of the total radiation, in various solar-altitude and spectrum affected by atmospheric conditions. Spectral Range: 315 to 400nm Response time: 1 second (90% response) Temperature response: 1.5% (range of -10 to +40°C) Non-linearity: Less than ±2.0%