The OL 200B is a 1000-W DXW irradiance standard lamp. These lamps have tungsten coiled-coil filaments enclosed in a small quartz envelope. The spectral irradiance calibration of this lamp covers the 750-2500 nm wavelength but 1000-W DXW lamps have the ability to be calibrated out to 4500 nm.
The Spectral Irradiance standards issued by Optronic Laboratories are based on the National Institute of Standards and Technology (NIST) Spectral Irradiance Scale
for the wavelength range of 250 to 2400 nm and on a blackbody for the wavelength range above 2400 nm. The NIST Scale has an uncertainty (k=2) of 0.63% in the visible, 1.56% in the ultraviolet at 250 nm, and 0.31% in the infrared at 2000 nm.
Calibration of the 1000-W DXW lamps are available with two levels of accuracy: high-accuracy and super high-accuracy. The High-Accuracy Standards of Spectral Irradiance issued by Optronic Laboratories have a transfer uncertainty (k=2) relative to the NIST Scale of ± 1-2%. The Super High-Accuracy Standards have a transfer uncertainty relative to the NIST Scale of ± 0.5%.