Dark Current.- 


These are the values obtained for gain and readout noise:
 

Up-Left Quad  Down-left Quad Up-Right Quad Down Right Quad Average
Gain (e per ADU) 4.18 4.25 4.16 4.15 4.18
Readout noise (e) 21.63 22.95 22.48 20.92 21.99

These are the parameter obtained with  polyfit of IRAF to calculate the parameters of the fitting for each graph (in all the cases the correlation was over 0.999). The polynomial used for the fitting is of third order:

Statistic for up-left quadrant:
Integration time 
Mean
Median
StdDev
1
2.63
2.59
7.11
2
2.79
2.76
10.28
5
3.45
3.25
20.08
10
4.43
3.77
39.43
15
4.71
4.10
49.23

Statictic for down-left quadrant:
Integration time 
Mean
Median
StdDev
1
2.60
2.48
7.81
2
2.68
2.92
8.69
5
3.36
3.07
12.98
10
4.49
4.36
21.04
15
4.91
3.97
29.59

Statistic for up-right quadrant:
Integration time 
Mean
Median
StdDev
1
2.5
2.13
8.07
2
2.40
1.95
10.41
5
3.17
2.76
18.93
10
4.05
3.85
33.46
15
4.49
3.90
45.67

Statictic for down-right quadrant:
Integration time 
Mean
Median
StdDev
1
2.08
2.10
8.12
2
2.33
2.06
9.02
5
3.09
3.22
12.42
10
4.11
3.59
19.39
15
4.36
4.08
26.68

Statictic for whole frame:
Integration time 
Mean
Median
StdDev
1
1.75
2.32
8.66
2
1.92
2.18
10.29
5
2.62
3.02
16.58
10
3.62
3.70
28.87
15
3.97
3.70
38.03

You can see that the median is more or less constant, independ of the integration time. This fact is different to the statistic done during Feb99, when the median  depended clearly with the exposure time. The shape of the curve is almost but much smaller. More studies have to be done to clearyfy this point.

Here you can see the results obtained during Feb99.