This is the FULL plot for the stability of the GIRAFFE flat field calibration
lamps. The plot is based on ROBOTIC flats (flattype=ROB) taken several times a week.
All 5 fibre systems (on two plates) are illuminated by the same flat lamp.
Since June 2006, the HC flats are measured for all five slit systems.
Before that date, they were taken for Medusa1 and Medusa2 only. </font><p><font size="2">

The average flux is obtained by dividing the average signal in the first raw
file by the EXPTIME.