*** SXT entrance filter transmission  ***

This table indicates times of SXT entrance filter 
failures. At these times the straylight within 
the instrument increased and the sensitivity of 
the instrument for low energy x-rays increased. 
The column labelled "values" indicates our best 
guess at the fraction of entrance filter open area
after each failure.

Note that the event of 11-Feb-2000 is not an actual
entrance filter failure. It has been included in 
this set for data processing reasons.

---- date & time --------- values ----
30-AUG-91  02:30:00      0.00000
13-NOV-92  18:00:00      0.0833333
16-AUG-95  08:04:20      0.166667
24-AUG-96  07:00:00      0.250000
24-JAN-98  00:00:00      0.333333
30-JAN-99  23:17:00      0.416667
12-MAR-99  02:00:00      0.500000
20-APR-99  19:02:00      0.583333
11-FEB-00  13:00:20      0.583333
14-DEC-01  21:12:16      --------
--------------------------------------