Automatic Span Calibration With Load Cell Data - Siemens SIWAREX WP241 Manual

Scale parameters and functions of the belt scale
8.5 Calibration of weight measurement
Step 2
1. Switched the belt on again. The calibration weight is secured on the scale.
2. Start recording of the weight for the parameterized number of belt revolutions using the
command "Start span calibration with test weight" (61). The status display in DR30
indicates that the calibration is running. The result is displayed in DR4.
3. Import the digits 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.
8.5.3

Automatic span calibration with load cell data

Automatic scale calibration
The automatic scale calibration, as an alternative to calibration with test weight, permits very
fast commissioning. However, the results are highly dependent on the correct mechanical
scale construction and the entered parameters.
The best scale accuracy can be achieved by calibrating with test weights or a test chain.
Following a certain period of operation, you can define further correction factors for the
material flow rate by means of a material test.
Requirements
The following requirements must be fulfilled in order to achieve successful automatic
calibration:
● Proper installation and alignment
● Load cells involved are equally and evenly loaded
● There are no shunt circuits
Step 1
The belt is warmed-up and the zero point has been determined. All relevant data has been
entered in DR10 (load cell parameters) and sent to the scale.
Step 2
Start the calculation using the command "Start automatic span calibration" (63). The result is
effective immediately and displayed in DR3 and DR4. Importing of the parameters to DR3 is
omitted.
Step 3
If the belt scale has not been installed exactly horizontally, enter the inclination angle of the
belt in data record DR15 and send this to the scale. The characteristic curve has thus been
determined. The scale can calculate the weight values for the complete measuring range.
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SIWAREX WP241
Manual, 04/2014, A5E33713528A