A new facility for measuring source irradiance was commissioned recently at the National Institute of Standards and Technology (NIST). The facility uses the calculable radiation from the Synchrotron Ultraviolet Radiation Facility (SURF III) as the primary standard. To measure the irradiance from a source under test, an integrating sphere-spectrometer-detector system measures both the source under test and the synchrotron radiation sequentially and the absolute irradiance from the source under test can be determined. In particular, we discuss the calibration of deuterium lamps using this facility from 200 nm to 400 nm. This facility improves current NIST UV irradiance scale to a measurement uncertainty of 1.2% (k=2).
Citation: Applied Optics
Pub Type: Journals
radiometric sources, synchrotron radiation, UV calibration