Atomic oscillators - comparisons

The modes of operation of the rubidium, caesium beam and passive hydrogen maser types of atomic oscillators are described. A comparison of precision crystal oscillators with their atomic counterparts shows the strengths and weaknesses of each. Over the long term, atomic oscillator costs can be comparable to or less than the costs associated with high quality quartz oscillators. This is due to the fact that calibration cycles are much less frequent with a resultant decrease of systems down time.