USNO Cesium Clocks

USNO Cesium Clocks

Most of the Observatory's cesium clocks are model HP5071A, made by Agilent Technologies, Inc. of Santa Clara, California. With an improved cesium tube and new microprocessor- controlled servo loops, the 5071A vastly outperforms the earlier 5061 cesium frequency standards. The Naval Observatory 5071A's feature HP's optional high-performance cesium beam tube, with accuracy 1 part in 10E12, frequency stability 8 parts in 10 to the 14th, and a time domain stability of < 2 parts in 10 to the 14th with an averaging time of 5 days. Other companies that produce cesium clocks include Datum, Inc. of Beverly, MA and Frequency Electronics, Inc. of Uniondale, NY.