I flew another test flight yesterday with the MS5525, and as usual it was initially ranging from 1-5m/s after power up, this is with the pitot tube covered, I then ran a pre-flight calibration action 2 or 3 times, that helped reduce the range a little, but it was still ranging from 1-3m/s. So, I then wanted to test manually zeroing the sensor, so I reduced the offset from -95 to -85, after that, it was reading from 0.0 to 0.1 on the HUD. I flew a set of flightlines that were 90 degrees to winds aloft, and the wind was quite light, and the airspeed matched the groundspeed along the flightlines within 0-1m/s when cruising along the flightlines in both directions, and when returning to launch, I can tell airspeed was matching the MIN_AIRSPEED parameter which was set to 18m/s.
So, this method of manually zeroing the sensor works, you just have to adjust the offset until you get the airspeed to readout values just above zero.
I still think the self calibration algorithm needs to be adjusted for this sensor, its not the same as the older 4525, and once zeroed, its a far superior airspeed sensor.
Please let me know if there's anything else I can do to help get this issue resolved.