BSI's scale of spectral irradiance

FEL lamp used for calibrations

Calibrations performed at Biospherical Instruments are traceable to the scale of spectral irradiance maintained by the National Institute of Standards and Technology (NIST). NIST distributes this scale in the form of 1000 W tungsten-halogen lamps of type FEL. An article describing how this scale is maintained at BSI is here.