The OL 752-10U Seasoned Spectral Irradiance calibration covers the wavelength range of 250 to 2500 nm. It consists of a compact, 200-W tungsten-halogen lamp operating at a color temperature of about 3000 K. The short working distance of 13 cm results in irradiance levels significantly higher than that normally obtained with higher wattage standards. The combination of greater precision in optical alignment and higher irradiance levels provides for a more accurate calibration of the spectroradiometer. Calibration of the OL 752-10 is based on the NIST High-Accuracy Scale of Spectral Irradiance. The NIST Scale has a reported uncertainty that varies from ± 2% at 250 nm to ± 1% in the visible. The OL 752-10 has a transfer uncertainty relative to the NIST Scale that varies from ± 1.5% in the ultraviolet to ± 1% in the visible-near infrared.
