Omar,
Monday, 17 Aug
Ito did not want to start w/ 3 g tests until measured the magnification.  So, today we ran random (100 gal) and sine (500 gal) tests.  Horizontal magnifications are very good.  Vertical changed from 8.6 at 37 Hz to 6 at 46.2, so I think wings are working quite well.  We have not had any "sync input" errors from the controller, but we have had 2 e-stops from the pump PLC.  Only occurs when have all 3 pumps running.  Never happens w/ just 1 or 2 pumps.
I have to look over the report on the wings you sent Ito; there are some sentences that even I don't understand immediately, but I will figure them out.
Yutaka figured out a way to improve coherence for STEX, so it looks like the problem at 12 Hz (oil column) for the low-level tests goes away.  Table noise today is about 2 gal, cuz the 'hood is noiser.  With hydraulics off, we get just a little less, about 1.6 to bigger at 2.5 gal.  So, cannot really measure the ambient noise level of the system; it's too damn quiet.  On Friday late, we had only 0.5 gal w/ hydraulics on and about the same w/ hydraulics off.
The system continues to purr like a pussycat.  I can tune the system so we are within the kind of specs I did at hud (<3% flat error).  STEX can get Kobe standard earthquake to within 1%.  Shock spectrum comes in at about 3% error for 3% analysis damping.
No doubt about it; NTT is the best earthquake system I have ever seen.
Rod Larson
