Performance of the PTB's primary clocks CS2 and CS1

摘要

Since the summer of 1985, two primary cesium atomic clocks have been in continuous operation in the PTB. The long-term performance of the two clocks is described, based on a 700-day data set. The output frequencies of the two clocks agree within their combined figures of uncertainty. Some features of the construction, and the evaluation of the uncertainty of one of the clocks are discussed.