This whole brouhaha about "steam quality" is ridiculous (and bogus). First, the "wet steam" supposed energy loss notion is denied by the "no-steam" experiment/demonstration, the data from which can be found on the LENR-CANR website and many other places, yet in all these threads is totally ignored.
And a capacitance probe certainly CAN measure "steam quality". It is simply a question of re-calibration to match the conditions used. I suspect such calibration data is available from the manufacturer, but if not, it's certainly possible to set up a simple rig to do so.
But even THAT is not necessary, as all that is required to know whether the steam is "wet" or "dry" is an accurate temperature measurement inside and the knowledge of barometric pressure in the lab at the time readings were taken. The temperature sensors used in all experiments were platinum RTD's, the most accurate and stable thermal sensors currently available to technology. Calibrations (even NBS certified calibrations) can be had for such sensors, and we know that the atmospheric pressure WAS measured in the lab, because Galantini said it was.
I have only just started reading up on these measurements and it sounds like sparging is the best approach.