Buck Research Instruments, LLC Cryogenic Hygrometer CR-1A

Benefits of the CR-1A • Wide Range: down to -120 °C (< 1 ppb) • Fast Response Time: typically 10-20 seconds • Inherent Stability and Accuracy • NIST-traceable • Very Low Maintenance The CR-1A is a high performance, cryogenically cooled hygrometer. CR-1 instruments have been routinely used aboard NASA aircraft and elsewhere for years. The CR-1A is a miniaturized version of the original CR-1, and uses a much smaller LN2 dewar. Operating time per filling of LN2 ranges from 6 to 8 hours, depending on the dew points being measured. A ±0.1% accuracy pressure transducer is included for measuring mixing ratio (ppmv or lbs/MMSCF). There is an optional 4.5 Ah battery pack, and an optional autofill system for continuous use applications. The CR-1A is designed to operate with virtually no attention. Maintenance demands are minimal, consisting of dewar filling and occasional mirror cleaning as necessary.