The new cryogenic vacuum chamber and black-body source for infrared calibrations at the NIST's FARCAL facility

The Facility for Advanced Radiometric Calibrations (FARCAL) at the National Institute of Standards and Technology (NIST) in Gaithersburg, MD, comprises the Medium Background Infrared (MBIR) facility and the Training for Calibration Expertise in Radiometry (TraCER), the latter being a classroom setting. The MBIR is a 120 cm by 180 cm vacuum chamber with an internal cold shroud and an integral roll-out table. The chamber will contain a black-body source and an absolute cryogenic radiometer (ACR). Both components are mounted on the roll-out table. Measurements will be performed in the MBIR facility that cannot be accomplished using existing facilities, including the NIST Low Background Infrared (LBIR) facility and the room-temperature non-vacuum radiometric facilities. Initially the MBIR facility will be used for 80 K medium background measurements and 300 K ambient background measurements.