Medium-background radiometric facility for calibration of sources or sensors

A new Medium-Background Facility (MBF) for the calibration of infrared sources and sensors has been designed by specialists from the All-Russian Research Institute for Optophysical Measurements (VNIIOFI) under contract to the Xi'an Institute of Applied Optics (China). The facility consists of several detachable modules, the configuration of which can be changed to suit the requirements of a specific task. The modular design allows flexible and independent use of the main components and simplifies upgrading. The facility was designed to allow absolute radiometric calibration of black-body sources and IR sensors; to compare the radiometric scale with predictions for measured temperatures; to allow measurements over an extended temperature range (up to the indium point); and to serve as the IR spectral radiance standard. Intended for the calibration of IR sensors and sources under vacuum conditions (10(-3) Pa) and a medium-background environment (liquid-nitrogen-cooled shroud), the MBF is briefly described with reference to its design, operating principles and measurement results.