The CryoRad II is the first universal cryogenic electrical substitution radiometer, designed for convenient detector calibrations with both laser, lamp or monochromator illumination. It’s novel cavity design enables use with beams as fast as f/8 without changing or moving the receiver. Its fast cavity response removes background drifts and provides noise thresholds below 2 nW, even with an f/8 entrance aperture and viewing an ambient-temperature window. The highest accuracy (0.005%) is achieved in laser beam measurements with a Brewster-angled window. In monochromator measurements, the sensitivity and accuracy are a factor 5 – 10 better than achieved with room temperature ESR’s. The CryoRad II is now in use at metro-logy laboratories throughout the world, for a wide range of photo-detector calibrations. CryoRad versions available for laser, monochromatic, synchrotron, or low background IR applications.

• CryoRad II Product Information Sheet