VEGA WEIGHTRAC 31 4 … 20 mA_HART - four-wire - Manual (Page 52)

52
7 Setup with PACTware
WEIGHTRAC 31 • 4 … 20 mA/HART - four-wire
42374-EN-131119
Static linearization
During static linearization you simulate a typical loading of the con-
veyor belt with a known quantity of material on a defined belt length.
Enter the adjustment points in kg/m.
Tip:
To ensure that the material is loaded onto the belt continuously and
without loss, we recommend the use of a ready-made wooden frame.
•
You have a known quantity of material lying in typical way and at a
typical height on a short section of the conveyor belt.
•
You know the later, continuous belt speed or can measure it.
•
The conveyor belt is loaded as completely as possible (100 %).
•
You can slowly move the conveyor belt manually.
If you do not have the option of moving the conveyor belt slowly by
hand and the materials are light weight, place the material on a long
piece of foil that you slowly pull through the measuring frame. In case
the weight of the foil is not negligible, you should add the weight of the
foil to the total weight later on.
Make sure that you do not reach into the control area of the measur-
ing plant. Cut the foil to an appropriate length.
1. Make sure that the source container is closed and locked (operat-
ing position: Off)
2. Load the conveyor belt evenly with a known quantity of material,
for example 60 kg over a length of 1 m.
Make sure that the material type and loading height corresponds
to the material that is measured later on.
3. Move the stretch of material into the measuring frame of
WEIGHTRAC 31.
4. Switch on the source container.
5. Click to "Start measurement".
6. Slowly move the belt manually or move the material slowly by
pulling on the foil. This process should take 5 to 10 minutes.
7. Click to "Stop measurement".
8. The measured count rate is stated in ct/s. This is the number of
counts per second, i.e. the measured radioactive radiation dose
actually reaching the sensor.
9. Now enter the corresponding material quantity (e.g. kg, t, lb). In
this case, this is the total material quantity lying on the conveyor
belt during the measurement.
Enter the length of the portion of belt used (e.g. 1 m).
This assigns a corresponding material quantity to the actual pulse
rate (e.g. 60 kg/m).
10. Click to "Complete".
Accept the value pair with "Accept".
11. Repeat this procedure with a larger quantity of material (e.g.
120 kg) until you have reached the max. loading height of the
conveyor belt.