Example Of A Recalibration Procedure - Seca 374 Service Manual

Vogel & Halke
Created on: 30.06.1998
Holger Panier / SE
Pressing the kg/lbs key for less than 1.5 seconds causes the weight shown on the display
to be increased or decreased by 10 g (depending on the mode currently selected). As the
resolution of the display is lower, the displayed value will not necessarily be increased or
decreased each time the kg/lbs key is pressed. Repeat the above procedure until the
displayed weight and the test weight match. Set the scales to the middle between two
division values by additionally incrementing or decrementing the value by n=d/(2*10). The
calibration process can now be completed by pressing the kg/lbs key for at least five
seconds. The scales compute and store a new linearity coefficient and will then be switched
off automatically. The scales are now calibrated. Remove the test weight.
Note
:
To prevent improper calibration by improper use, a timeout control has been implemented
in the calibration mode, i.e. the time that passes until the next key is pressed must never
exceed five seconds.
However, this timeout control is only active for the phase when switching to the calibration
mode.
If, during this phase, 5 seconds have passed and no key has been pressed, the scales are
automatically restored to the weighing mode so that the procedure must be repeated.
To reduce calibration errors to a minimum, recalibration is only possible using a test weight
of more than 25% and less than 100% of the max. load; otherwise, "Er:0:15" will appear
on the display.
If the scales need to be set to a different GAL value, the displayed value must be matched
to the test weight value adapted to the GAL value correction.

Example of a recalibration procedure:

The selected test weight is 100 kg.
The current weight shown on the display is 99.7 kg (max. difference of 300 g).
In this example, you must switch the scales to the incrementing mode to carry out the
recalibration procedure. After the kg/lbs key has been pressed (for more than 1.5 seconds),
a flashing "inc" is shown.
Now increase the value by the first 10 g (by briefly pressing the kg/lbs key). After this has
been done thirty times, the value 100.0 (rounded!) appears on the display although the
internal measured value still is 99.95 kg (not rounded!).
To correct this rounding error, increase the value by another 10 g to get exactly 100.00 as
the calculated value.
Terminate the recalibration procedure as described above.
File: 00603_e1.doc
Printed on: 07.07.1999
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00603_e1.doc