Berthold LB 442, Operating Manual

Page: 77 / 158

Section 7 Calibration
75
Normally it suffices to work with a linear absorption coeffi-
cient.
o Select calibration mode lin/squ/cub/auto. Calibration is per-
formed as soon as you confirm the calibration mode with < en-
ter >.
o Then you can call the results with < more >: depending on the
selected calibration mode: a
1
describes the linear, a
2
the square
and a
3
the cubic coefficient.
o You may use the square error to assess the quality of the calcu-
lated calibration curve. If this value is greater than 10
-4
, the
calibration is not OK.
If more than three calibration points are used, we recom-
mend to plot a x/y graph. The weight per area is plotted on
the y axis and the logarithmic value of the count rate on the
x axis. The visual presentation of the calibration allows a
very good assessment of the quality of the calibration and is
very helpful in trouble-shooting the calibration.