Communication 
  11.6 Calibration of weight measurement 
SIWAREX WT241 
Manual, 05/2015, A5E36046748Aa  113 
11.6.4  Span calibration by test chain 
Span calibration by test chain 
If the scale is loaded with a chain (e.g. 50% of the nominal load), the weight is assigned to 
the new digital value returned by the analog-to-digital converter. 
Step 1 
The belt is warmed-up and the zero point has been determined.  
1.  Stop the belt. 
2.  Enter a test chain corresponding to the measuring range in DR3 (e.g. 50% of the nominal 
load). 
3.  Place the test chain onto the scale. 
Step 2 
1.  Switched the belt on. The test chain is positioned on the scale. 
2.  Start recording of the weight for the parameterized number of belt revolutions using the 
command "Start span calibration with test chain" (65). The status display in DR30 
indicates that the calibration is running. The result is displayed in DR4. 
3.  Import the working point into DR3 using the command "Apply span calibration digits" (89). 
The characteristic curve has thus been determined. The scale can calculate the weight 
values for the complete load range. 
11.6.5  Span calibration with known material flow 
Span calibration with known material flow 
The material test is usually used to determine the correction factor of a calibrated scale. 
However, a known quantity of material can also be used to carry out a scale calibration. The 
calibration is based on transportation of a known quantity of material, and comprises the 
following steps: 
Step 1 
The belt is warmed-up and the zero point has been determined.