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Weighing Functions
5.2.41 DR3 - Smallest set weight ∑min
If the scale is supposed to be used as an automatic weighing instrument with
weight totalising, the smallest set weight (load) must be defined. The scale will only
start a weighing procedure if the set value for the overall quantity is higher than this
limit value.
5.2.42 DR3 - Totalising value dt
If the scale is supposed to be used as an automatic weighing instrument with
weight totalising, a scaling value must be defined. The total of several weighing
procedures is output with this scaling value.
5.3 Theoretical Adjustment – Adjustment Without Adjustment Weights
If performing the adjustment is not possible using adjustment weights, the scale
can also be put back into operation without adjustment weights, if the mechanical
structure of the scale is correct and the measuring logs are available for the
individual load cells. Execution is handled with the help of SIWATOOL FTA during
the processing of the adjustment parameters. We call the procedure "theoretical
adjustment".
First, the characteristic value range (1mV/V, 2mV/V or 4mV/V) must be defined in
the "Adjustment" tab of the data record for the adjustment data. Then, switch to the
"Theoretical adjustment" tab.
To execute the theoretical adjustment, the rated load for all load cells is defined
first, e.g. 3 load cells with 1,000 kg each result in a rated load of 3,000 kg.
The adjustment zero offset (unit μV), and the characteristic value (unit mV/V) is
then entered for each individual load cell. These values are taken from the
respective load cell measurement log. The characteristic value is normally entered
with up to 5 decimal places, e.g. 2.01201.
Adjustment zero offset for each load cell is defined as follows:
Adjustment zero offset (μV) = Adjustment zero offset measurement value (μV/V) x
Weigh module supply voltage (V)
Example:
Load cells - Supply voltage (EXC) = 10 V
Adjustment zero offset = 1.2 μV/V (from Load cells - measurement log)
Entry: Adjustment zero offset = 1.2 μV/V x 10 V = 12 μV
After entering the data for each load cell, the adjustment digits are calculated and
the result is displayed by actuating the button "Calculate adjustment digits". Then,
the calculated adjustment digits can be integrated into the data record with
adjustment data (DR 3) by actuating button "Accept calculation". The data record is
then sent to the weigh module with the new adjustment data.
Depending on the mechanics of the device, a completely empty scale may indicate
a value that deviates from the adjustment zero slightly. In this case, the instruction
"Characteristic curve shift" can be executed.
5-60
SIWAREX FTA
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