6.4.9 How to use the snapshot function to filter parasitic signals
The thresholds cannot find the level of the tank contents if it is below a large parasitic signal.
This shows the signals as you can see them on an oscilloscope:
But you can filter a parasite or an area of parasites with the snapshot function. This procedure
tells you how to use the snapshot filter:
•
Look at the signal screen in operator mode.
i
Find the likely position of the parasite.
•
Look in the tank or at a drawing of internal tank parts.
i
Get the dimensions and position of the object that shows as the parasite.
•
Empty the tank.
•
Go to Supervisor > Quick Setup > Setup Mode > Snapshot
Supervisor > Quick Setup > Setup Mode > Snapshot
Supervisor > Quick Setup > Setup Mode > Snapshot
Supervisor > Quick Setup > Setup Mode > Snapshot
•
Do the procedure.
•
Save the settings.
•
Make sure that the snapshot filter is on.
•
Fill the tank.
i
The device will ignore the large parasite signal and use the first signal it finds.
Figure 6-11: Voltage/distance graph: level below a large parasitic signal
1
Voltage amplitude of the signal in Volts
2
Distance from the process connection
3
Large parasitic signal (an agitator in this example)
4
Threshold
5
Level signal
9
3
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Instruction Manual
Tek-Flex
4100A
