Berthold LB 442, Operating Manual

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Section 8 Checking the Calibration
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Which Calibration Points are Calculated?
The evaluation computer calculates the calibration curve (absorp-
tion coefficients) from the measured values. All calibration points
are used for this calculation where the parameters count rate,
speed, measuring time and comparative weight contain valid val-
ues (> zero). When entering invalid parameters or if invalid pa-
rameters (zero) are present, the respective calibration point is not
taken into account in the calculation. All unused calibration points
should be deleted.
8.2 Correction of Display Value
This option should not be regarded as a substitute for a careful
calibration. It should only be used if minor corrections are required
when in the load display. Otherwise we recommend to run a re-
calibration.
An additive constant can be entered at Offset , a multiplication fac-
tor at Factor ( Calibrate menu, submenu Calculate ).
8.2.1 Offset
The value stored under Offset is added to the load. This allows a
parallel offset of the calibration curve. This means an offset of the
tare value. We recommend using the factor to correct the display
value.
8.2.2 Factor
The load is multiplied by the value stored as Factor . This allows
you to change the gradient of the calibration curve.
Formula
The display value is calculated as follows:
Display (t/h) = Factor x Measured value (t/h) +
Offset
Measured value (t/h) : Calculated load using the current count
rate without taking into account factor and offset.