SUMMARY
The new data - the first since the central bearing replacement - appear nominal, and show only minor changes from data taken prior to the engineering.

   Datasets     HST start      mean leg temperatures   Humidity
                               start   middle   end       %
 ( inc990502      10:04         1.7     2.7     3.8      40 )
   inc990508      17:23         n/a     n/a     n/a      20

Inclinometry
There were noticeable changes in the zero-points of most of the relevant inclinometry channels, but nothing to worry about in terms of linearity or overflow, and these fairly cosmetic changes can be adjusted out at an appropriate moment. The difference between the new model and the previous one of 990502 is shown below :

• The agreement is not bad considering the trauma, with barely any change at all in F2 and F3, but showing a strong +2" sawtooth (~sin(2*azimuth)) change in F1. The rms scatters in the (F1,F2,F3) differences are (1.38", 0.37", 0.63").
• The symmetry remains good (see the plot ).
• The new track model was installed at 22:00 HST on 19990508 - although it will undoubtedly be superseded before any observing occurs.

Strain Gauge Data
In the new measures the G1 strain gauge data peak at azimuths 104.54, 187.74, 284.54 and 367.74 ( wheels 4,3,2,1 resp) - exactly as before. The sign of the G2 data remain enigmatic : while they will be fully incorporated eventually, they are essentially ignored here. The results below are baseline corrected, and are given in raw units :

       wheel      4           3           2          1    |   Total
               -------     -------     -------    ------- |  -------
   dataset     G1   G2     G1   G2     G1   G2    G1   G2 |  G1   G2
               -------     -------     -------    ------- |  -------
  inc990403   114  -17    299  -48    215  -45   132  -10 | 760 -120
  inc990404   104  -16    297  -48    204  -45   129  -11 | 734 -120
  inc990309   105   -4    249  -29    167  -37    94   -5 | 615  -75
  inc990311    66   -6    253  -34    187  -39   103   -4 | 609  -83
  inc990501    84  -11    260  -23    229  -21   123  -15 | 696  -70
  inc990508    75  -12    248  -22    283  -16    84  -13 | 582  -63
     990510_1  63  -11    224   -2    143    3    53    5 | 483   -5

The current wheel loading appears to be about 84% of that prior to the engineering. The fractional loads on wheels (4,3,2,1) are now (0.13, 0.43, 0.30, 0.14) c.f. (0.12, 0.37, 0.33, 0.18) previously; or as ratios : 1.0 : 3.3 : 2.3 : 1.1 c.f. 1.0 : 3.1 : 2.8 : 1.5   previously.