Berthold LB 444 - Correcting the Results: Addition and Multiplication; Additive Constant; Multiplication Factor

Density Meter LB 444 SECTION 6. BASICS OF DENSITY MEASUREMENTS
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6.6 Correcting the Results: Addition and Multiplication
This option should not be regarded as a substitute for a careful calibration. It
should only be used if minor corrections are required. Otherwise we recommend
a re-calibration.
An additive constant can be entered at Offset, a multiplication factor at Factor
(Calibrate menu, submenu Calculate).
Additive Constant
The value stored under Offset is added to the density value calculated on the
basis of the countrate. This allows a parallel shift of the calibration curve.
Example:
Measuring range 1.1 - 1.3 g/cm
3
It is found that the measuring values are too low by 0.05 g/cm
3
.
Remedy:
Enter “0.05” at Offset.
All measured values will be increased by 0.05 g/cm
3
.
Instead of 1.1 g/cm
3
, 1.15 g/cm
3
is now indicated and instead of 1.3 g/cm
3
, 1.35
g/cm
3
. If the measured values would be too high by 0.05 g/cm
3
, you would have
to enter “-0.05”.
6.6.2 Multiplication Factor
Each measuring value is multiplied by the value stored as Factor. This allows
you to change the gradient of the calibration curve.
Example:
Measuring range 1.1 - 1.3 g/cm
3
If you enter 1.1 at Factor, 1.21 g/cm
3
will be displayed instead of 1.1 g/cm
3
. In-
stead of 1.3 g/cm
3
the value 1.43 g/cm
3
is now displayed. Thus even the low
point of the measuring range is increased, provided it is not at 0.
Remedy:
This can be corrected by entering the appropriate data at Offset at Factor.
Example:
For 1.1 g/cm
3
the indicated value is correct; instead of 1.2 g/cm
3
the reading
should show 1.25 g/cm
3
.
Input value for Factor:
F =
H - L
H - L
=
1.25 g / cm - 1.1 g / cm
1.2 g / cm - 1.1 g / cm
nominal nominal
actual actual
33
33
= 1.5