This is the basis for the well - known cesium clock, presently the standard of frequency and time.
这就是众所周知的铯原子钟的基础，它是目前的频率和时间基准。
2
This uncertainty is one of the critical factors governing the accuracy level of the cesium fountain frequencystandard.
此项频移误差是决定铯原子喷泉频标准确度总体水平的主要因素之一。
3
A portable laser system, continually working for very long period, is the key part in realization of an optically pumped cesium beam frequencystandard.