@Adam Equipment Company 2004
4
4.0 REMOVING THE COVER
If it becomes required to remove the cover, you should be very careful as
pulling or pressing on the load cell during this procedure can damage it very
easily, especially on the lower capacity balances.
When removing the screws (1 screw for the plastic pan support and 4 small
screws below the scale) hold the cover to the base and ensure not to press on
the balance case as the load cells can be damaged.
On some units the load cell is attached to the cover, on larger capacity units
the load cell is attached to the base.
The load cells are protected by overload and under-load stops. These stops
are either plates that contact the cover or screws that are accessible from the
outside of the scales.
Refer to the Trouble-shooting Guide for the possible causes of any problem.
5.0 LOAD CELL DAMAGE
If a problem is suspected with the load cell or A/D converter press the
[Units]
key and then turn the scale ON to observe the A/D counts. The counts should
go from a smaller value (typically 2000-8000) to a larger value as weight is
added to the pan. The value shown should also be stable.
If the A/D counts are outside this range or cannot be seen then it will be
necessary to trouble shoot the load cell, load cell connections to verify the
load cell is working correctly and has not been damaged.
The most common reason for a scale to fail is that the load cell has been
damaged. The damage can be due to two primary causes. The first is the
physical damage due to an overload or an impact from the side and the
second is damage due to the environment, such as moisture, extreme heat or
a cut cable if the cables are exposed.
With the AQT scale it is possible the load cell is damaged such that the scale
still operates when the scale is calibrated but not when a small mass is put on
the pan. This will become apparent when the scale reads correctly at the
calibration mass but is not correct at lower masses. The scale may still zero
OK after power is applied but it will not register a weight value for smaller
weights.
Check the A/D counts in this case.
