KERN & SOHN ABT 220-5DM - Manual (Page 20)

ABT-BA-e-1312 20
8 Adjustment
As the acceleration value due to gravity is not the same at every location on earth,
each balance must be coordinated - in compliance with the underlying physical
weighing principle - to the existing acceleration due to gravity at its place of location
(only if the balance has not already been adjusted to the location in the factory). This
adjustment process must be carried out for the first commissioning, after each
change of location as well as in case of fluctuating environment temperature. To re-
ceive accurate measuring values it is also recommended to adjust the balance peri-
odically in weighing operation.
Observe stable environmental conditions. Stabilisation requires a warm-up period of
1 or 4 hours (for models d = 0.01 mg). Ensure that there are no objects on the
weighing plate.
8.1 Automatic adjustment via PSC
The default setting for balances of the series ABT ("PSC ON") prompts automatic
adjustment via the PSC function.
The moment a change in temperature is detected this function uses the internal tare
weight to carry out fully-automatic adjustment with the help of a temperature sensor.
If PSC is left ON, when there is a temperature change that would influence sensitivi-
ty, span calibration executes automatically to maintain the sensitivity of the balance.
Adjustment in weighing mode is carried out automatically under the following condi-
tions:
(1) If a change in environmental temperature (0.5 °C) occurs;
(2) When about four hours has passed since the previous calibration.
(3) When the balance is switched from standby status to weighing mode
and condition (1) or (2) has been met.
(4) When balance was disconnected from the mains.
If one of the above conditions was met in weighing mode, the weight symbol flashes
for about two minutes in order to notify the pending adjustment; afterwards the dis-
play will show "PSC run". During operation, the display will automatically change and
the motor sound of the weight loading system is heard. In order to ensure proper
PSC operation, prevent vibrations and air flow. As soon as the display in grams re-
appears after completing adjustment via PSC, the balance returns to weighing mode.
The sensitivity before and after adjustment is slightly different. Also, no measure-
ments can be made during adjustment. To prevent a start-up of adjustment during a
measuring process you have to actuate the [ON/OFF] key as soon as the weight
symbol starts flashing. This will interrupt automatic adjustment.