BERTHOLD TECHNOLOGIES LB 444, Operating Manual

Page: 35 / 127

04/03
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LB 444
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Coefficient a1
Linear absorption coefficient (range -10 to +10).
Enter this coefficient for one-point calibration or use the default value for Cs-137 (-
0.066). This value also has to be confirmed with <enter> .
One-point calibration is carried out as soon as you press the < enter > button.
Zero count rate Io
The zero count rate is automatically calculated for calibration. It corresponds to the zero
point of the unit of measure, i.e. the density or concentration value “0”.
The zero count rate is automatically corrected at midnight, compensating for the source
decay. Do not change it manually.
Coefficient a1
The calculated or entered coefficient a1 is displayed. Do not change it manually; this also
applies to coefficients a2 and a3.
Coefficient a2
Square absorption coefficient. This value is automatically calculated for two- or multi-
point calibration.
Coefficient a3
Cubic absorption coefficient. This value is automatically calculated for multi-point calibra-
tion.
Square error
This value is calculated automatically for two- or multi-point calibration. It indicates the
quality of the calibration curve for the selected calibration mode. The smaller the numeri-
cal value, the better the curve fit (see chapter 8 CALIBRATION). This coefficient is not a
criterion for selection of the best calibration mode (see calibration mode
auto ).
Factor
Enter a multiplication factor (0 to 10) to correct the measured values. Each measured
value is multiplied by this factor. It allows you to change the slope of the calibration
curve. When performing a new calibration, the factor is automatically set to “1” (see also
chapter 8.5.2).
Offset
Additive correction of the measured values; allows parallel offset of the curve. The offset
entered here is added to each measured value. When performing a new calibration, the
value is automatically set to “0” (see also chapter 8.5.1).
Calibration value
Only for temperature compensation via Pt 100 or current input:
The temperature compensated lab values are displayed which were entered at rates 1. to
10. (g/cm
3
). Scroll with < + > and < - >. The calibration curve is calculated using these
values.