Our lab has GPS disciplined rubidium freqency standard (Datum 9390-6000) and two free running rubidium frequency standards with 1pps synch options. One of those free running standards is Stanford Research PRS10 and another FS725. My main goal is to check annually the PRS10 and FS725 conditions, that they meet accuracy spesification +/-5E-11 per day. I have also posibility to use Keysight 53230A frequency counter for this evaluation. Can someone explain me what is most straigh forward method to do frequency spesification evalution for PRS10 and FS725 10MHz outputs?
The 53230A is adequate for a quick check of the Rubidium standards, but not calibration. They are about the same accuracy, E-11 at best. GPS is a little better at E-12. To calibrate them, you need something better like a Cesium standard, which is in the E-14 range. We beat the Cesium standard against the house standard and do stats for the difference, and plot each over time. Then we can calculate the long term stability and drift rate.