> What is the reference used to measure stability and accuracy > of H Masers?
Antonio, Good question. You compare against other H-maser(s), or an ensemble of Cs clocks, or high-precision coax, fiber, or two-way satellite links to other timing laboratories that happen to have much better clocks. In general, when you have a really good clock in your lab, the obvious way to measure its performance is to find a clock that is 10x more accurate and compare your clock against it. But if you can't find a better reference, or can't afford a better reference, or if a better reference doesn't even exist, then you use a different trick -- you make two or three clocks of the same design and compare them amongst themselves. > Do Caesium clocks have something like a C-field adjustment > (as Rb clocks have), and in the case, what it acts upon? Yes, all commercial Cs clocks do have a C-field adjustment or an internal phase micro-stepper (frequency offset generator). This is useful since they are generally more stable (parts in 1e-13 to 1e-15) than they are accurate (parts in 1e-12 to 1e-13). So the C-field is the traditional way to fine-tune the frequency of the clock. Modern Cs clocks find it easier (and perhaps more reliable) to adjust by synthesizer than by magnetic field. On the other hand, laboratory Cs standards correct for all these systematic effects and are thus about as accurate as they are stable. If you'd like more details, let me know. > Thanks in advance, > > Antonio I8IOV /tvb _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
