This report hosts correlation plots for the monitoring of the GIRAFFE
linearity and gain, derived from image flats. These data are taken
about monthly. Since 2008-07, they are acquired with the
common detector monitoring template and reduced with the corresponding common
recipe.</font><p><font size="2">

Note the CCD upgrade between 2008-03 and 2008-05. Plots #3 and 4 are available
for the new CCD only. </font><p><font size="2">

A sequence of image flats is exposed
between 0.5 and 220 secs. Their average exposure level is plotted against the
exposure time (box 1). The fitted function corresponds to 
mean = 245*exptime for the old CCD, and  195*exptime for the new CCD. In box 3, 
non-linear residuals are plotted vs. exposure time (new CCD only). </font><p><font size="2">

PLot 4 (for the new CCD only) shows the GAIN values plotted over exposure
time. The asymptotic value for texp -> 0 is the true GAIN. The value stored in
the file headers is indicated as "nominal". </font><p><font size="2">

Find the trending of non-linearity coefficient and gain <a
href=trend_report_DETLIN_HC.html target=_blank>here</a>.