AEC OS Series Gravimetric Batch Blenders - Manual (Page 59)

Page 58 of 118
5-8-3 Weigh Hopper (Load Cell) Calibration
Enter the diagnostics menu as described previously. See Section 5-3
for menu tree.
The factory pre-calibrates the weigh hopper on the OS/OA blenders.
Menu #1 on the Diagnostics Menu is “Calibration”. Press <1> to enter
the scale calibration menu.
Once in Scale Calibration, the display will prompt the user to empty the
weigh hopper and press the key. Make sure that the hopper is
empty, and then put the hopper back on line. The blender controller will
read the load cell reading and use this setting as the Zero weight point of
the weigh hopper with no material.
Important! It is imperative at this time that there is no mechanical binding of
any kind on the weigh hopper. Adjust the load cell stops as
described on page 45.
Once the zero weight has been set and the user has pressed the
key, the controller will indicate to the user to set the calibration
weight on the scale and press the key.
At this point, the calibration weight provided with the blender should be
placed on the weigh hopper through the calibration slot. After this is
done, press the key.
Then key in the value that is stamped on the calibration weight, and
press the key to enter the calibration constant value.
The controller will read the current value of the load cell and will use this
and the Zero weight calibration to set the span of the load cell.
The controller will indicate the current amount of weight on the scale.
The display will prompt the user to remove the calibration weight. It will
remain at this display until the weight reading is lower than 0.5 lbs. or
kilograms. The program will then return to the calibration menu,
indicating that the scale calibration procedure is finished.
If for some reason the calibration of the load cell varies by 10% from the
calibration originally done at the factory, the control will indicate that it
has detected a calibration error. At this time, it is advisable to go back
through the calibration routine in case an error was made. During this
procedure, check the A/D calibration numbers that are displayed on the
screen. If the calibration still varies more than 10%, the following display
will be indicated to the operator.