Using MCMC fitting to the sensing function measurements made in ER10 and O2, we can establish an estimate on the variation of the optical response parameters. The table below gives the typical (simple mean), maximum, and minimum of the measured maximum a posteriori values from the MCMC fits.

Parameter             typical    maximum    minimum
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Gain (ct/m)           1.143e6    1.166e6    1.085
Cavity pole (Hz)      347.1      358        341
Time delay (usec)     0.5        2.5        -1.3
Detuned spring (Hz)   7.3        8.8        4.9
Detuned spring 1/Q    0.04       0.08       1e-3

This covers measurement dates from Nov 07 2016 through Mar 06 2017.

Attached are plots showing these trends for ER10 and O2. Note that I have added--where possible--the GDS calculated values for kappa_C and f_c (black crosses). Note that these values do not come with error bars because the uncertainty would need to be computed from the measurement uncertainty of what goes into the calculate of kappa_C and f_c. It would be useful to have calibration lines running during the measurements to see if there is any trend or drift during the measurements themselves.